Document:

EX-10.8

 EXHIBIT 10.8 

ARATANA THERAPEUTICS, INC. 
 EMPLOYMENT AGREEMENT 
 This EMPLOYMENT
AGREEMENT (this “Agreement”) is made and entered into as of March 12, 2013 by and between ARATANA THERAPEUTICS, INC. (the
“Company”) and Ernst Heinen (the “Executive”). The Company and the Executive are hereinafter collectively referred to as the “Parties”, and individually referred to as a
“Party”. 
 RECITALS 

A. The Executive is currently employed by the Company pursuant to the terms of an Offer Letter dated April 28, 2012 (the “Offer
Letter”). 
 B. The Company desires to continue to employ the Executive. 

C. The Executive desires to accept such continued employment by the Company, subject to the terms and conditions set forth in this
Agreement, effective as of March 12, 2013 (such date being referred to herein as the “Effective Date”). 
 AGREEMENT 
 In consideration of the foregoing Recitals and
the mutual promises and covenants herein contained, and for other good and valuable consideration, the Parties, intending to be legally bound, agree as follows: 
 1. Employment. 
 1.1 Offer and Acceptance of Employment. The Company
hereby agrees to employ the Executive, and the Executive hereby accepts such employment with the Company, in each case effective as of the Effective Date and otherwise subject to the terms and conditions set forth in this Agreement. 

1.2 Title. The Executive’s position shall be designated as Head of Drug Evaluation and Development, subject to the terms and
conditions set forth in this Agreement. 
 1.3 Term. The term of this Agreement shall begin on the Effective Date and
shall continue until terminated pursuant to Section 4 herein (the “Term”); provided, however, that the Parties expressly acknowledge and agree that the Executive’s employment with the Company is at will and
may, subject to the provisions of Section 4, be terminated by the Company or by the Executive at any time for any reason or for no reason. 
 1.4 Duties. During the Term, the Executive shall (a) perform such services as are normally associated with the position of Head of Drug Evaluation and Development and (b) report to the
Company’s President and Chief Executive Officer. 

  
 -1-

 1.5 Policies and Practices. The employment relationship between the Parties shall be
governed by this Agreement and by the policies and practices established by the Company and the Company’s board of directors (the “Board”). In the event that the terms of this Agreement differ from or are in conflict
with the Company’s policies or practices as in effect from time to time, this Agreement shall control. 
 1.6
Location. Unless the Parties otherwise agree in writing, during the Term the Executive shall perform the services the Executive is required to perform pursuant to this Agreement at a business office established by the Company in the Kansas City,
KS metropolitan area; provided, however, that the Company may from time to time require the Executive to travel temporarily to other locations in connection with the Company’s business. 

2. LOYAL AND CONSCIENTIOUS PERFORMANCE; NONCOMPETITION.

 2.1 Loyalty. During the Executive’s employment by the Company, the Executive shall devote the Executive’s
full business energies, interest, abilities and productive time to the proper and efficient performance of the Executive’s duties under this Agreement; provided, however, that, subject to Section 2.2 and Section 2.3 and
provided that such activities do not materially interfere with the performance of the Executive’s duties under this Agreement, the Executive may participate in the activities listed on Exhibit A attached hereto, as well as charitable,
community or civic activities, and any other activities that may be disclosed by the Executive in writing in advance to, and approved by, the Board after the date hereof. 
 2.2 Covenant Not to Compete. The Executive acknowledges and agrees that the business of the Company is global in scope. The Executive further acknowledges and agrees that during the course of his
employment with the Company he will learn confidential information relating to the Company and its business and business strategies and will develop business relationships on behalf of the Company at the Company’s expense. The Executive
acknowledges and agrees that if he were to divert this information and the relationships to a competitor, the Company would suffer irreparable harm to its business and goodwill in an amount that cannot be readily quantified. Accordingly, the
Executive agrees that during the Term and the Noncompetition Period (as defined below), the Executive shall not engage in competition with the Company and/or any of its Affiliates (as defined below), either directly or indirectly, in any manner or
capacity, as adviser, principal, agent, Affiliate, promoter, partner, officer, director, employee, stockholder, owner, co-owner, consultant or member of any association or otherwise, in any phase of the business of developing, licensing,
manufacturing, distributing or marketing of products or services that are in the same Field of Use (as defined below) or which are otherwise in competition with the actual or reasonably anticipated products or services of the Company at the time of
his separation from the Company, except with the prior written consent of the Board. For purposes of this Agreement: (i) “Noncompetition Period” means the period of six (6) months following the
termination of the Executive’s employment for any reason; and (ii) “Field of Use” means companion animal therapeutic products marketed, developed or manufactured by the Company, including any potential products with
respect to which the Company is actively engaged in in-licensing discussions as of the commencement of the Noncompetition Period, or such products known to the Executive to be under development by the Company. The Executive acknowledges and agrees
that because of the global scope of the Company’s business, this restriction shall cover the United States of America and Europe. 

  
 -2-

 For purposes of this Agreement, “Affiliate” means, with respect to any specific
entity, any other entity that, directly or indirectly, through one or more intermediaries, controls, is controlled by or is under common control with such specified entity. Ownership by the Executive in professionally managed funds over which the
Executive does not have control or discretion in investment decisions or as a passive investment of less than two percent (2%) of the outstanding shares of capital stock of any corporation identified on Exhibit C attached hereto or with
one or more classes of its capital stock listed on a national securities exchange or publicly traded on a national securities exchange or in the over-the-counter market shall not constitute a breach of this Section 2.2. 

2.3 Covenant Not To Solicit. The Executive agrees that during the Term and for one (1) year following the termination of his
employment for any reason, he shall not, directly or indirectly, solicit or recruit any employees of the Company to terminate their work for the Company or to perform services in competition with the Company. 

2.4 Acknowledgement Regarding Indemnification. The Company and the Executive expressly acknowledge and agree that the Executive
shall, at all times during the Term of this Agreement, be deemed to be and qualify as an “executive officer” for purposes of Article XI of the Company’s bylaws as in effect as of the Effective Date and shall be entitled to all of the
rights and remedies relating to the indemnification of executive officers of the Company pursuant thereto. 
 3.
COMPENSATION OF THE EXECUTIVE. 
 3.1 Base Salary. The
Company shall pay the Executive a base salary at the rate of Two Hundred Seventy-Five Thousand U.S. Dollars ($275,000.00) per year (the “Base Salary”), less payroll deductions and all required withholdings, payable in regular
periodic payments in accordance with the Company’s normal payroll practices. The Base Salary shall be prorated for any partial year of employment on the basis of a 365-day fiscal year. The Base Salary shall be subject to review and adjustment
from time to time by and at the sole discretion of the Board or any committee thereof. 
 3.2 Annual Bonus. The Executive
shall have a targeted annual cash performance bonus (the “Bonus”) payment of thirty-five percent (35%) of the Base Salary with respect to each calendar year, subject to the Executive’s continued employment with the
Company as of the end of such calendar year and contingent upon (a) successful achievement of corporate objectives established from year to year by the Board, which objectives may be modified by the Board, and/or (b) other adjustments that
the Board deems appropriate. Any Bonus pursuant to this Section 3.2 shall be paid as promptly as practicable following the end of the applicable calendar year, but not later than March 15th of the following calendar year. 

  
 -3-

 3.3 Equity Compensation. 

3.3.1 Stock Option. 
 (i) Subject to Board approval, promptly following an initial public offering of the Company’s stock (the “IPO”) , the Company shall grant the Executive an incentive stock option (the
“Stock Option”) pursuant to the Company’s then in effect equity incentive plan or similar plan (the “Plan”) to purchase up to 50,000 shares of the Company’s common stock (the
“Common Stock”), at the Common Stock’s fair market value as determined in good faith by the Board as of the date of such grant. 
 (ii) The Stock Option shall be granted subject to the terms and conditions of the Plan and a written option agreement to be entered into by the Company and the Executive (the “Option
Agreement”). The Option Agreement shall provide, among other things, that the shares of Common Stock underlying the Stock Option (the “Option Shares”) shall vest: (x) as to 1/4th of the Option Shares, upon the first
(1st) anniversary of the date of grant of the Stock Option; and (y) as to the remaining Option Shares, in equal monthly installments over the next thirty-six (36) months such that all shares shall be vested as of the fourth
(4th) anniversary of the date of grant of the Stock Option, subject to the Executive’s continued employment with the Company on each such vesting date; provided, however, that: (a) the Stock Option shall be subject to
accelerated vesting as provided in Section 3.3.3, Section 4.5.1 and Section 4.5.3(iii); and (b) “early exercise” of the Stock Option shall be permitted pursuant to the terms of the Plan and the Option Agreement.

 3.3.2 Restricted Stock Award. [Intentionally omitted] 

3.3.3 Double-Trigger Acceleration. In the event that the Executive’s employment with the Company is terminated by the
Company (or its successor) without Cause (as defined below) or by the Executive for Good Reason (as defined below) on account of or within twelve (12) months following the date of the consummation of a Change in Control (as defined below) (such
period, the “Double-Trigger Period”), the vesting and exercisability of each of the Executive’s outstanding stock awards (including any stock options, restricted stock or other awards granted to the Executive by the
Company) shall be automatically accelerated in full. 
 3.4 Expense Reimbursements. The Company will reimburse the
Executive for all reasonable business expenses the Executive incurs in conducting his duties hereunder, pursuant to the Company’s usual expense reimbursement policies, provided that the Executive supplies the appropriate substantiation for such
expenses. Any amounts payable under this Section 3.4 shall be made in accordance with Treasury Regulation Section 1.409A-3(i)(1)(iv) and shall be paid on or before the last day of the Executive’s taxable year following the taxable
year in which the Executive incurred the expenses. The amounts provided under this Section 3.4 during any taxable year of the Executive’s will not affect such amounts provided in any other taxable year of the Executive’s, and the
Executive’s right to reimbursement for such amounts shall not be subject to liquidation or exchange for any other benefit. 

3.5 Employment Taxes. All of the Executive’s compensation shall be subject to all applicable federal, state and local taxes
and withholdings, as well as any others that the Company determines it is legally required to withhold. 

  
 -4-

 3.6 Benefits. The Executive shall, in accordance with Company policy and the terms of
the applicable plan documents, be eligible to participate in benefits under any benefit plan or arrangement, including any 401K plan with Company matching, disability insurance plan and life insurance plan, that may be in effect from time to time
and made available to the Company’s senior management employees, including with respect to additional coverage for spouses, domestic partners and eligible dependents. 
 3.7 Vacation. The Executive shall be entitled to three (3) weeks’ paid vacation time per year and five (5) days’ paid personal time per year, subject to a maximum accrual of
three (3) weeks. 
 4. TERMINATION. 

4.1 Termination by the Company. The Executive’s employment with the Company is at will and may be terminated by the Company at
any time and for any reason, or for no reason, including, but not limited to, under the following conditions: 
 4.1.1
Termination by the Company for Cause. The Company may terminate the Executive’s employment under this Agreement for Cause by delivery of written notice to the Executive specifying the Cause or Causes relied upon for such termination.
Any notice of termination given pursuant to this Section 4.1.1 shall effect termination as of the date of the notice, or as of such other date as specified in the notice. 
 4.1.2 Termination by the Company Without Cause. The Company may terminate the Executive’s employment under this Agreement without Cause at any time and for any reason, or for no reason,
by delivery of written notice to the Executive. Any notice of termination given pursuant to this Section 4.1.2 shall effect the termination of the Executive’s employment hereunder as of the date of such notice, or as of such other date as
is specified in such notice. 
 4.2 Termination by the Executive. The Executive’s employment with the Company is at
will and may be terminated by the Executive at any time and for any reason, or for no reason, including, but not limited to, under the following conditions: 
 4.2.1 Termination by the Executive for Good Reason. The Executive may terminate his employment under this Agreement for Good Reason in accordance with the procedures specified in Section 4.6.2
below. 
 4.2.2 Termination by the Executive Without Good Reason. The Executive may terminate his employment under this
Agreement for other than Good Reason at any time. 
 4.3 Termination for Death or Complete Disability. The
Executive’s employment with the Company shall automatically terminate effective upon the date of the Executive’s death or Complete Disability (as defined below). 
 4.4 Termination by Mutual Agreement of the Parties. The Executive’s employment with the Company may be terminated at any time upon a written mutual agreement of the Parties. Any such
termination of employment shall have the consequences specified in such agreement. 

  
 -5-

 4.5 Compensation Upon Termination. 

4.5.1 Death or Complete Disability. If the Executive’s employment shall be terminated by death or Complete Disability as
provided in Section 4.3, the Company shall pay to the Executive, or to the Executive’s heirs, as applicable, the Base Salary and accrued and unused vacation benefits earned through the date of termination at the rate in effect at the time
of termination, plus all other amounts to which the Executive is entitled under any compensation plan or practice of the Company at the time of termination, less standard deductions and withholdings. In addition, the vesting and/or exercisability of
each of the Executive’s outstanding stock awards (including any stock options, restricted stock or other awards granted to the Executive by the Company) shall be automatically accelerated on the date of termination as to the number of stock
awards that would have vested over the twelve (12) month period following the date of termination had the Executive remained continuously employed by the Company during such period. The Company shall thereafter have no further obligations to
the Executive and/or to the Executive’s heirs under this Agreement, except as otherwise provided by law. 
 4.5.2 With
Cause or Without Good Reason. If the Executive’s employment is terminated by the Company for Cause, or if the Executive terminates his employment hereunder without Good Reason, the Company shall pay to the Executive the Base Salary
and accrued and unused vacation benefits earned through the date of termination at the rate in effect at the time of termination, plus all other amounts to which the Executive is entitled under any compensation plan or practice of the Company at the
time of termination, less standard deductions and withholdings. The Company shall thereafter have no further obligations to the Executive under this Agreement, except as otherwise provided by law. 

4.5.3 Without Cause or for Good Reason. If the Company terminates the Executive’s employment without Cause or the Executive
terminates his employment hereunder for Good Reason, the Company shall pay to the Executive the Base Salary and accrued and unused vacation benefits earned through the date of termination at the rate in effect at the time of termination, plus all
other amounts to which the Executive is entitled under any compensation plan or practice of the Company at the time of termination, less standard deductions and withholdings. In addition, subject to the Executive’s: (i) furnishing to the
Company an executed waiver and release of claims in substantially the form attached hereto as Exhibit B (which form may be amended to comply with legal requirements arising after the Effective Date) (the “Release”) no
later than forty-five (45) days following the Executive’s termination; and (ii) allowing the Release to become effective in accordance with its terms, the Executive shall be entitled to the following: 

(i) payment in an amount equal to fifty percent (50%) of the Executive’s annual Base Salary in effect at
the time of termination (but determined prior to any reduction in the Base Salary that would give rise to the Executive’s right to voluntarily resign for Good Reason pursuant to Section 4.6.2), less standard deductions and withholdings,
paid in equal installments over a period of six (6) months pursuant to the Company’s standard payroll practices (the “Cash Severance”); and 

  
 -6-

 (ii) should the Executive elect to continue Company- sponsored group
health insurance benefits in accordance with the provisions of COBRA or State Continuation, as applicable, following the date of termination, to the extent that doing so will not result in adverse tax consequences or violate applicable law, the
Company shall pay the full premium for such group health insurance continuation benefits for the Executive and any eligible dependents for a period of six (6) months after the effective date of the Release; provided, however, that
any such payments will cease if the Executive voluntarily enrolls in a health insurance plan offered by another employer or entity during the period in which the Company is paying such premiums. The Executive agrees to promptly notify the Company in
writing of any such enrollment. For purposes of this Section 4.5.3(ii), references to COBRA or State Continuation premiums shall not include any amounts payable by the Executive under an Internal Revenue Code Section 125 health care
reimbursement plan. 
 4.6 Definitions. For purposes of this Agreement, the following terms shall have the following
meanings: 
 4.6.1 Complete Disability. “Complete Disability” shall mean the inability of the
Executive to perform the Executive’s duties under this Agreement, even with reasonable accommodation, because the Executive has become permanently disabled within the meaning of any policy of long-term disability income insurance covering
employees of the Company then in force. In the event the Company has no policy of disability income insurance covering employees of the Company in force when the Executive becomes disabled, the term “Complete Disability” shall mean the
inability of the Executive to perform the Executive’s duties under this Agreement, even with reasonable accommodation, by reason of any incapacity, physical or mental, which the Board, based upon medical advice or an opinion provided by a
licensed physician mutually acceptable to the Board and the Executive, determines to have incapacitated the Executive from satisfactorily performing all of the Executive’s usual services for the Company, even with reasonable accommodation, for
a period of at least one hundred twenty (120) days during any twelve (12) month period (whether or not consecutive). Based upon such medical advice or opinion, the determination of the Board shall be final and binding and the date such
determination is made shall be the date of such Complete Disability for purposes of this Agreement. 
 4.6.2 Good Reason.
“Good Reason” for the Executive to terminate his employment hereunder shall mean the occurrence of any of the following events without the Executive’s consent: 

(i) a material diminution in the Executive’s authority, duties or responsibilities relative to his authority,
duties or responsibilities in effect immediately prior to such reduction; 

  
 -7-

 (ii) a material change in the geographic location at which the
Executive must perform his duties to a point that is located more than fifty (50) miles from the outer limits of the Kansas City, KS metropolitan area; 
 (iii) a material diminution by the Company of the Executive’s base compensation as initially set forth herein or as the same may be increased from time to time; or 

(iv) any other action or inaction that constitutes a material breach by the Company or any successor or Affiliate
of its obligations to the Executive under this Agreement; provided, however, that such termination by the Executive shall only be deemed for Good Reason pursuant to the foregoing definition if: (x) the Executive gives the Company
written notice of the intent to terminate for Good Reason within thirty (30) days following the first occurrence of the condition(s) that the Executive believes constitutes Good Reason, which notice shall describe such condition(s);
(y) the Company fails to remedy such condition(s) within thirty (30) days following receipt of the written notice (the “Cure Period”); and (z) the Executive terminates his employment within thirty
(30) days following the end of the Cure Period. 
 4.6.3 Cause. “Cause” for the
Company to terminate the Executive’s employment hereunder shall mean the occurrence of any of the following events, as determined by the Board or a committee designated by the Board, in its sole discretion: 

(i) the Executive’s conviction of any felony or any crime involving moral turpitude or dishonesty; or against
the Company; 
 (ii) the Executive’s participation in a fraud involving 

(iii) the Executive’s willful and material breach of the Executive’s duties hereunder that is not cured
within thirty (30) days after the Executive’s receipt of written notice from the Board of such breach; 

(iv) the Executive’s intentional and material damage to the Company’s property; or 

(v) the Executive’s material breach of the Non- Disclosure and Assignment Agreement (as defined below);

 provided, however, that prior to the determination that Cause under this Section 4.6.3 has occurred, the Company shall:
(w) provide to the Executive in writing, in reasonable detail, the reasons for the determination that such Cause exists; (x) other than with respect to clause (iii) above which specifies the applicable period of time for the Executive
to remedy his breach, afford the Executive a reasonable opportunity to remedy any such breach; (y) provide the Executive an opportunity to be heard prior to the final decision to terminate the Executive’s employment hereunder for such
Cause; and (z) make any decision that such Cause exists in good faith. 

  
 -8-

 4.6.4 Change in Control. “Change in Control” shall
mean the occurrence, in a single transaction or in a series of related transactions, of any one or more of the following events: (i) there is consummated a merger, consolidation or similar transaction involving (directly or indirectly) the
Company if, immediately after the consummation of such merger, consolidation or similar transaction, the stockholders of the Company immediately prior thereto do not own, directly or indirectly, either (a) outstanding voting securities
representing more than fifty percent (50%) of the combined outstanding voting power of the surviving entity in such merger, consolidation or similar transaction or (b) more than fifty percent (50%) of the combined outstanding voting
power of the parent of the surviving entity in such merger, consolidation or similar transaction; (ii) the stockholders of the Company approve or the Board approves a plan of complete dissolution or liquidation of the Company, or a complete
dissolution or liquidation of the Company shall otherwise occur; or (iii) there is consummated a sale of all or substantially all of the consolidated assets of the Company and its subsidiaries, other than a sale of all or substantially all of
the consolidated assets of the Company and its subsidiaries to an entity more than fifty percent (50%) of the combined voting power of the voting securities of which entity is owned by stockholders of the Company in substantially the same
proportion as their ownership of the Company immediately prior to such sale; provided, however, that the term “Change in Control” shall not include a sale of assets, merger or other transaction effected exclusively for the
purpose of changing the domicile of the Company. 
 4.7 Survival of Certain Sections. Sections 2.2, 2.3, 2.4, 4, 5, 6, 7,
8, 9, 12, 13, 16 and 18 of this Agreement will survive the termination of this Agreement. 
 4.8 Parachute Payment. If any
payment or benefit the Executive would receive pursuant to this Agreement (each, a “Payment”) would: (i) constitute a “Parachute Payment” within the meaning of Section 280G of the Internal Revenue Code of
1986, as amended (the “Code”); and (ii) but for this sentence, be subject to the excise tax imposed by Section 4999 of the Code (the “Excise Tax”), then such Payment shall be reduced to the Reduced Amount.
The “Reduced Amount” shall be equal to the largest portion of the Payment (including all of it) which, after taking into account all applicable federal, state and local income and employment taxes (all computed at the highest
applicable marginal rate), and the Excise Tax, if applicable, results in the Executive’s receipt, on an after-tax basis, of the greatest amount of the Payment, whether or not all or some portion of the Payment is subject to the Excise Tax. If a
reduction in payments or benefits constituting Parachute Payments is necessary so that the Payment equals the Reduced Amount, reduction shall occur in the following order unless the Executive elects in writing a different order (provided,
however, that such election shall be subject to Company approval if made on or after the effective date of the event that triggers the Payment): reduction of cash payments; cancellation of accelerated vesting of stock awards; reduction of
employee benefits. In the event that acceleration of vesting of stock award compensation is to be reduced, such acceleration of vesting shall be cancelled in the reverse order of the date of grant of the Executive’s stock awards unless the
Executive elects in writing a different order for cancellation. Notwithstanding anything to the contrary set forth herein, the Executive may not elect the order in which the reduction in the Executive’s payments or benefits will occur if such
election would cause any such amounts to constitute “nonqualified deferred compensation” within the meaning of Section 409A of the Code such that the Executive would incur the additional twenty percent (20%) tax under
Section 409A of the Code (the “409A Tax”). In addition, if a different order of reduction is required to avoid the 409A Tax, that order shall apply. 

  
 -9-

 The accounting firm then engaged by the Company for general audit purposes shall perform the
foregoing calculations. The Company shall bear all expenses with respect to the determinations by such accounting firm required to be made hereunder. 
 The accounting firm engaged to make the determinations hereunder shall provide its calculations, together with detailed supporting documentation, to the Executive and the Company within fifteen
(15) calendar days after the date on which the Executive’s right to a Payment is triggered (if requested at that time by the Executive or the Company) or such other time as requested by the Executive or the Company. If the accounting firm
determines that no Excise Tax is payable with respect to a Payment, either before or after the application of the Reduced Amount, it shall furnish the Executive and the Company with an opinion reasonably acceptable to the Executive that no Excise
Tax will be imposed with respect to such Payment. Any good faith determinations of the accounting firm made hereunder shall be final, binding and conclusive upon the Executive and the Company. 

4.9 Application of Internal Revenue Code Section 409A. Notwithstanding anything to the contrary set forth herein, any Cash
Severance amounts that constitute “nonqualified deferred compensation” within the meaning of Section 409A of the Code shall not commence in connection with the Executive’s termination of employment unless and until the Executive
has also incurred a “separation from service” within the meaning of Section 409A of the Code, unless the Company reasonably determines that such amounts may be provided to the Executive without causing the Executive to incur the 409A
Tax. To the extent any Cash Severance amounts: (i) are paid following the date of termination of the Executive’s employment through March 15 of the calendar year following such termination, such severance benefits are intended to
constitute separate payments for purposes of Section 1.409A-2(b)(2) of the Treasury Regulations and thus payable pursuant to the “short-term deferral” rule set forth in Section 1.409A-1(b)(4) of the Treasury Regulations;
(ii) are paid following said March 15, such Cash Severance benefits are intended to constitute separate payments for purposes of Section 1.409A-2(b)(2) of the Treasury Regulations made upon an involuntary separation from service and
payable pursuant to Section 1.409A-1(b)(9)(iii) of the Treasury Regulations, to the maximum extent permitted by said provision; and (iii) are in excess of the amounts specified in clauses (i) and (ii) of this paragraph, shall
(unless otherwise exempt under Treasury Regulations) be considered separate payments subject to the distribution requirements of Section 409A(a)(2)(A) of the Code, including, without limitation, the requirement of Section 409A(a)(2)(B)(i)
of the Code that payments or benefits be delayed until six (6) months and one (1) day after the Executive’s separation from service if the Executive is a “specified employee” within the meaning of the aforesaid section of
the Code at the time of such separation from service. In the event that a six (6) month and one (1) day delay of any such separation payments or benefits is required, on the first regularly scheduled pay date following the conclusion of
the delay period the Executive shall receive a lump sum payment or benefit in an amount equal to the separation payments and benefits that were so delayed, and any remaining separation payments or benefits shall be paid on the same basis and at the
same time as otherwise specified pursuant to this Agreement (subject to applicable tax withholdings and deductions). 

  
 -10-

 5. CONFIDENTIAL AND PROPRIETARY
INFORMATION. As a condition of employment, the Executive agrees to execute and abide by the Company’s standard form of Non-Disclosure and Proprietary Rights Assignment Agreement (the “Non-Disclosure and
Assignment Agreement”). 
 6. ASSIGNMENT AND BINDING
EFFECT. This Agreement shall be binding upon and inure to the benefit of the Executive and the Executive’s heirs, executors, personal representatives, assigns, administrators and legal representatives. Because
of the unique and personal nature of the Executive’s duties under this Agreement, neither this Agreement nor any rights or obligations under this Agreement shall be assignable by the Executive. This Agreement shall be binding upon and inure to
the benefit of the Company and its successors, assigns and legal representatives. Any such successor of the Company will be deemed substituted for the Company under the terms of this Agreement for all purposes and the Company will require any
successor to all or substantially all of the business or assets of the Company expressly to assume and to agree to perform this Agreement in the same manner and to the same extent that the Company would be required to perform it if no such
succession had taken place. For this purpose, “successor” means any person, firm, corporation or other business entity which at any time, whether by purchase, merger or otherwise, directly or indirectly acquires all or substantially all of
the assets or business of the Company. 
 7. NOTICES. All notices or demands of any kind
required or permitted to be given by the Company or the Executive under this Agreement shall be given in writing and shall be personally delivered (and receipted for) or faxed during normal business hours or mailed by certified mail, return receipt
requested, postage prepaid, addressed as follows: 
 If to the Company: 

Aratana Therapeutics, Inc. 
 1901 Olathe Boulevard 
 Kansas City, KS 66103 

Attention: Chairman of the Board 
 If to the Executive, to the address set forth on the signature page hereto. 
 Any such written
notice shall be deemed given on the earlier of the date on which such notice is personally delivered or three (3) days after its deposit in the United States mail as specified above. Either Party may change its address for notices by giving
notice to the other Party in the manner specified in this section. 
 8. CHOICE OF
LAW. This Agreement shall be construed and interpreted in accordance with the internal laws of the State of Delaware. The Executive and the Company consent to non-exclusive personal jurisdiction in any state and, if
otherwise permitted by law, federal court situated in the State of Delaware for the resolution of all claims arising under this Agreement that are subject to resolution in court rather than through arbitration. 

  
 -11-

 9. INTEGRATION. This Agreement, including Exhibit A,
Exhibit B, and Exhibit C, together with the Non-Disclosure and Assignment Agreement, contains the complete, final and exclusive agreement of the Parties relating to the terms and conditions of the Executive’s employment and the termination of
the Executive’s employment, and supersedes all prior oral and written employment agreements or arrangements between the Parties, including but not limited to the Offer Letter. 

10. AMENDMENT. This Agreement cannot be amended or modified except by a written agreement signed by
the Executive and the Company. 
 11. WAIVER. No term, covenant or condition of this
Agreement or any breach thereof shall be deemed waived, except with the written consent of the Party against whom the wavier is claimed, and any waiver or any such term, covenant, condition or breach shall not be deemed to be a waiver of any
preceding or succeeding breach of the same or any other term, covenant, condition or breach. 
 12.
SEVERABILITY. The finding by a court of competent jurisdiction of the unenforceability, invalidity or illegality of any provision of this Agreement shall not render any other provision of this Agreement
unenforceable, invalid or illegal. Such court shall have the authority to modify or replace the invalid or unenforceable term or provision with a valid and enforceable term or provision, which most accurately represents the Parties’ intention
with respect to the invalid or unenforceable term, or provision. 
 13. INTERPRETATION;
CONSTRUCTION. The headings set forth in this Agreement are for convenience of reference only and shall not be used in interpreting this Agreement. This Agreement has been drafted by legal counsel representing the
Company, but the Executive has been encouraged to consult with, and has consulted with, the Executive’s own independent counsel and tax advisors with respect to the terms of this Agreement. The Parties acknowledge that each Party and its
counsel has reviewed and revised, or had an opportunity to review and revise, this Agreement, and any rule of construction to the effect that any ambiguities are to be resolved against the drafting party shall not be employed in the interpretation
of this Agreement. 
 14. REPRESENTATIONS AND WARRANTIES. The
Executive represents and warrants that the Executive is not restricted or prohibited, contractually or otherwise, from entering into and performing each of the terms and covenants contained in this Agreement, and that the Executive’s execution
and performance of this Agreement will not violate or breach any other agreements between the Executive and any other person or entity. 
 15. COUNTERPARTS. This Agreement may be executed in two (2) counterparts, each of which shall be deemed an original, all of which together shall constitute one
and the same instrument. 
 16. ARBITRATION. To ensure the rapid and economical resolution
of disputes that may arise in connection with the Executive’s employment with the Company, the Executive and the Company agree that any and all disputes, claims, or causes of action, in law or equity, arising from or relating to the
Executive’s employment, or the termination of that employment, will be resolved, to the fullest extent permitted by law, by final, binding and confidential arbitration 

  
 -12-

 
pursuant to the Federal Arbitration Act in Kansas City, Kansas conducted by the Judicial Arbitration and Mediation Services/Endispute, Inc. (“JAMS”), or its successors, under the
then current rules of JAMS for employment disputes; provided that the arbitrator shall: (a) have the authority to compel adequate discovery for the resolution of the dispute and to award such relief as would otherwise be permitted by
law; and (b) issue a written arbitration decision including the arbitrator’s essential findings and conclusions and a statement of the award. ACCORDINGLY, THE EXECUTIVE AND THE COMPANY HEREBY IRREVOCABLY WAIVE ANY RIGHT TO A JURY TRIAL IN
ANY LEGAL PROCEEDING ARISING OUT OF OR RELATING TO THIS AGREEMENT. Both the Executive and the Company shall be entitled to all rights and remedies that either the Executive or the Company would be entitled to pursue in a court of law. The Company
shall pay any JAMS filing fee and shall pay the arbitrator’s fee. The arbitrator shall have the discretion to award attorneys’ fees to the party the arbitrator determines is the prevailing party in the arbitration; provided,
however, that the prevailing party shall be reimbursed for such fees, costs and expenses within sixty (60) days following any such award, but, to the extent the Executive is the prevailing party, in no event later than the last day of the
Executive’s taxable year following the taxable year in which the fees, costs and expenses were incurred; provided, further, that the Parties’ obligations pursuant to the provisos set forth above shall terminate on the tenth
(10th) anniversary of the date of the Executive’s termination of employment. Nothing in this Agreement is intended to prevent either the Executive or the Company from obtaining equitable relief in court to prevent irreparable harm pending
the conclusion of any such arbitration. Notwithstanding the foregoing, the Executive and the Company each have the right to resolve any issue or dispute involving a claim of misappropriation or infringement of confidential, proprietary or trade
secret information, or intellectual property rights, in any court of competent jurisdiction instead of via arbitration. 

17. TRADE SECRETS OF OTHERS. It is the understanding
and intention of both the Company and the Executive that the Executive shall not divulge to the Company and/or its subsidiaries any confidential information or trade secrets belonging to others, including the Executive’s former employers, nor
shall the Company and/or its Affiliates seek to elicit from the Executive any such information. The Executive shall not provide to the Company and/or its Affiliates or use on their behalf any such information or any documents or copies of documents
containing such information. 
 18. ADVERTISING WAIVER. The Executive agrees
to permit, during and following the term of this Agreement, and without receiving additional compensation, the Company, and persons or other organizations authorized by the Company, to use, publish and distribute advertising or sales promotional
literature concerning the products and/or services of the Company, or the machinery and equipment used in the provision thereof, in which the Executive’s name and/or pictures of the Executive taken in the course of the Executive’s
provision of services to the Company appear. The Executive hereby waives and releases any claim or right the Executive may otherwise have arising out of such use, publication or distribution. 

[REMAINDER OF PAGE INTENTIONALLY LEFT BLANK] 

  
 -13-

 IN WITNESS WHEREOF, the
Parties have executed this Agreement as of the date first written above. 
  

			
	ARATANA THERAPEUTICS, INC.
	
	/s/ Steven St. Peter
	By: 	 	Steven St. Peter
	Its:	 	President and CEO
	
	Dated:

			
	
	EXECUTIVE:
	
	/s/ Ernst Heinen
	Ernst Heinen
		
	Dated:	 	
		
	Address:	 	 
		
		 	 

  
 -14-

 EXHIBIT A 
 PERMITTED ACTIVITIES 
 None. 

 EXHIBIT B 
 RELEASE AND WAIVER OF CLAIMS 
 TO BE SIGNED FOLLOWING TERMINATION WITHOUT
CAUSE OR RESIGNATION 
 FOR GOOD REASON 
 In consideration of the payments and other benefits set forth in the Employment Agreement dated March 12, 2013 (the “Employment Agreement”), to which this form is attached, I,
Ernst Heinen , hereby furnish ARATANA THERAPEUTICS, INC. (the “Company”), with the following release and waiver (“Release and Waiver”). 

In exchange for the consideration provided to me by Section 4 of the Employment Agreement that I am not otherwise entitled to
receive, I hereby generally and completely release the Company and its directors, officers, employees, shareholders, partners, agents, attorneys, predecessors, successors, parent and subsidiary entities, insurers, Affiliates, and assigns from any
and all claims, liabilities and obligations, both known and unknown, that arise out of or are in any way related to events, acts, conduct, or omissions occurring prior to my signing this Release and Waiver, except claims that the law does not permit
me to waive by signing this Release and Waiver. This general release includes, but is not limited to: (1) all claims arising out of or in any way related to my employment with the Company or the termination of that employment; (2) all
claims related to my compensation or benefits from the Company, including salary, bonuses, commissions, vacation pay, expense reimbursements, severance pay, fringe benefits, stock, stock options, or any other ownership interests in the Company;
(3) all claims for breach of contract, wrongful termination, and breach of the implied covenant of good faith and fair dealing; (4) all tort claims, including claims for fraud, defamation, emotional distress, and discharge in violation of
public policy; and (5) all federal, state, and local statutory claims, including claims for discrimination, harassment, retaliation, attorneys’ fees, or other claims arising under the federal Civil Rights Act of 1964 (as amended), the
federal Americans with Disabilities Act of 1990, the federal Age Discrimination in Employment Act of 1967 (as amended) (“ADEA”), the Kansas Anti-discrimination Act and the Kansas Age Discrimination in Employment Act.

 Notwithstanding the foregoing, nothing in this Release and Waiver shall constitute a release by me of any claims or damages
based on any right I may have to enforce the Company’s executory obligations under the Employment Agreement, or my eligibility for indemnification under applicable law, Company governance documents or under any applicable insurance policy with
respect to my liability as an employee or officer of the Company, or my rights pursuant to my stock awards (including any stock options, restricted stock or other awards granted to me by the Company) pursuant to their terms. 

I acknowledge that, among other rights, I am waiving and releasing any rights I may have under ADEA, that this Release and Waiver is
knowing and voluntary, and that the consideration given for this Release and Waiver is in addition to anything of value to which I was already entitled as an executive of the Company. If I am 40 years of age or older upon execution of this Release
and Waiver, I further acknowledge that I have been advised, as required by the Older Workers Benefit Protection Act, that: (a) the release and waiver granted herein does not relate to claims under the ADEA which may arise after this Release and
Waiver is executed; (b) I should 

 
consult with an attorney prior to executing this Release and Waiver; (c) I have twenty-one (21) days from the date of termination of my employment with the Company in which to consider
this Release and Waiver (although I may choose voluntarily to execute this Release and Waiver earlier); (d) I have seven (7) days following the execution of this Release and Waiver to revoke my consent to this Release and Waiver; and
(e) this Release and Waiver shall not be effective until the seven (7) day revocation period has expired. 
 I
acknowledge my continuing obligations under my Non-Disclosure and Assignment Agreement. Pursuant to the Non-Disclosure and Assignment Agreement I understand that among other things, I must not use or disclose any confidential or proprietary
information of the Company and I must promptly return all Company property and documents (including all embodiments of proprietary information) and all copies thereof in my possession or control. I understand and agree that my right to the severance
pay I am receiving in exchange for my agreement to the terms of this Release and Waiver is contingent upon my continued compliance with my Non-Disclosure and Assignment Agreement. 

This Release and Waiver constitutes the complete, final and exclusive embodiment of the entire agreement between the Company and me with
regard to the subject matter hereof. I am not relying on any promise or representation by the Company that is not expressly stated herein. This Release and Waiver may only be modified by a writing signed by both me and a duly authorized officer of
the Company. 
  

									
	Date: 	 	 	 		  	By:	  	 
					
		 		 		  	Name: 	  	 

 EXHIBIT C 
 ADDITIONAL PERMITTED INVESTMENTS 
 None.EX-10.9(a)

 Exhibit 10.9(a) 

ARATANA THERAPEUTICS, INC. 
 2010 EQUITY INCENTIVE PLAN 
 Approved by the Board of Directors:
December 23, 2010 
 Approved by the Stockholders: December 23, 2010 

1. DEFINED TERMS. Capitalized terms in this Aratana Therapeutics, Inc. 2010 Equity Incentive Plan (the “Plan”)
shall have the meanings set forth in Appendix A attached hereto, unless defined elsewhere in this Plan or the context of their use clearly indicates a different meaning. 
 2. PURPOSES. The primary purpose of the Plan is to provide a means by which the Company can retain and maximize the services of its current Employees, Directors and Consultants, and secure,
retain and maximize the services of new Employees, Directors and Consultants, by providing Stock Awards, including Incentive Stock Options, Nonstatutory Stock Options, Restricted Stock Awards and stock bonuses, to such persons on the terms and
conditions set forth in the Plan. In addition, the Plan is intended to generate proceeds from the sale of Common Stock pursuant to Stock Awards that shall be used as general funds of the Company. 

3. ADMINISTRATION. 
 3.1 Authority of the Board. Unless and until the Board decides to delegate administration of the Plan to a Committee as set forth in Section 3.2 below, the Board shall have full authority to
administer the Plan, subject only to the express provisions and limitations set forth in the Plan and any applicable laws. Without limiting the generality of the foregoing, the Board shall be fully empowered to: (i) determine, from time to
time, the recipients of Stock Awards and the terms upon which Stock Awards shall be granted to such recipients; (ii) construe and interpret, and correct any defects, omissions or inconsistencies in, the Plan and any Stock Awards;
(iii) terminate, suspend or amend the Plan or any Stock Award as provided in Section 11; and (iv) exercise such powers and perform such acts consistent with the provisions of the Plan as the Board deems necessary or expedient to
promote the best interests of the Company and its stockholders. The determinations of the Board with respect to the Plan shall not be subject to review by any Person and shall be final, binding and conclusive on the Company and all other Persons.

 3.2 Delegation to Committee. In accordance with the Board’s authority under the relevant provisions of the
Delaware General Corporation Law and the Company’s bylaws, the Board may delegate administration of the Plan to a Committee, which shall, upon such delegation, be empowered to exercise the full authority of the Board with respect to the Plan.

 4. COMMON STOCK SUBJECT TO THE PLAN. 
 4.1 Reserve Pool. Subject to the provisions of Section 10 hereof relating to Capitalization Adjustments, an aggregate of 1,500,000 shares of Common Stock (the “Reserve
Pool”) may be issued pursuant to Stock Awards. If any Stock Award shall for any reason 

 
expire or otherwise terminate, in whole or in part, without having been exercised in full, the shares of Common Stock not acquired under such Stock Award shall automatically revert to the Reserve
Pool and again become available for issuance under the Plan. During the term of the Plan, the Company shall keep available in the Reserve Pool at all times a number of shares of Common Stock sufficient to satisfy all outstanding Stock Awards.

 5. ELIGIBILITY. 
 5.1 Employees. Employees shall be eligible to receive each of the types of Stock Awards provided for in the Plan. 
 5.2 Directors. Directors shall be eligible to receive each of the types of Stock Awards, except Incentive Stock Options, provided for in the Plan. 

5.3 Consultants. Consultants shall be eligible to receive each of the types of Stock Awards, except Incentive Stock Options,
provided for in the Plan; provided, however, that a Consultant shall not be eligible for the grant of a Stock Award if, at the time of the proposed grant, either the offer or sale of the Company’s securities to such Consultant
would not be exempt under Rule 701 of the Securities Act or the securities laws of any other relevant jurisdiction, unless the Company determines that the grant will otherwise comply with, or be exempt from, the Securities Act and the securities
laws of all other relevant jurisdictions. 
 5.4 Ten Percent Stockholders. In addition to any other applicable
restrictions set forth in this Section 5, a Ten Percent Stockholder shall not be granted: (i) an Incentive Stock Option, unless the exercise price of such Incentive Stock Option is at least one hundred ten percent (110%) of the Fair
Market Value of the Common Stock on the date of grant and such Incentive Stock Option is not exercisable after the expiration of five (5) years from the date of grant; (ii) a Nonstatutory Stock Option, unless the exercise price of such
Nonstatutory Stock Option is at least one hundred ten percent (110%) of the Fair Market Value of the Common Stock on the date of grant; or (iii) a Restricted Stock Award, unless the purchase price of the Common Stock issuable upon exercise
of such Restricted Stock Award is at least one hundred ten percent (110%) of the Fair Market Value of the Common Stock on the date of grant. 
 6. PROVISIONS APPLICABLE TO ALL STOCK AWARDS. 
 6.1 No
Stockholder Rights. No Participant shall be deemed to be the holder of, or to have any of the rights of a holder with respect to, any shares of Common Stock subject to any Stock Award held by such Participant unless and until such Participant
has satisfied all requirements for the exercise of the Stock Award pursuant to its terms. 
 6.2 No Employment or Other
Service Rights. Nothing in the Plan or any Stock Award Agreement shall confer upon any Participant any right to continue to serve the Company or an Affiliate in any capacity, or modify any agreement governing the employment of any Participant.
Likewise, nothing in the Plan or any Stock Award shall affect the right of the Company or any applicable Affiliate to terminate: (i) the employment of an Employee with or without notice and with or without Cause; (ii) the service of a
Consultant pursuant to the terms of such Consultant’s agreement with the Company or an Affiliate; or (iii) the service of a Director pursuant to the bylaws of the Company or any applicable Affiliate, and any applicable provisions of the
corporate law of the state in which the Company or the Affiliate is incorporated, as the case may be. 

  
 2 

 6.3 Investment Assurances. At any time that the issuance of the shares of Common
Stock issuable upon the exercise of a Stock Award has not been registered under an effective registration statement under the Securities Act, the Company may: (i) require a Participant, as a condition of acquiring Common Stock under such Stock
Award, to give written assurances satisfactory to the Company (a) as to the Participant’s knowledge and experience in financial and business matters and capability to evaluate the merits and risks of acquiring such Common Stock under such
Stock Award and (b) stating that the Participant is acquiring such Common Stock under the Stock Award for the Participant’s own account and not with any present intention of selling or otherwise distributing such Common Stock; and
(ii) place legends, including without limitation, legends restricting the transfer of such Common Stock, on any and all stock certificates representing such Common Stock in order to comply with applicable securities laws. 

6.4 Withholding Obligations. To the extent provided by the terms of a Stock Award Agreement, the Participant may satisfy any
federal, state or local tax withholding obligation relating to the acquisition of Common Stock under a Stock Award by any of the following means (in addition to the Company’s right to withhold from any compensation paid to the Participant by
the Company) or by a combination of any of such means: (i) tendering a cash payment; (ii) authorizing the Company to withhold shares of Common Stock from the shares of Common Stock otherwise issuable to the Participant as a result of the
acquisition of Common Stock under the Stock Award; provided, however, that no shares of Common Stock are withheld with a value exceeding the minimum amount of tax required to be withheld by law (or such lower amount as may be necessary
to avoid variable award accounting); or (iii) delivering to the Company owned and unencumbered shares of Common Stock. 

6.5 Vesting. The Board or Committee may provide that the total number of shares of Common Stock subject to a Stock Award shall
vest in installments over any given period of time. Criteria for determining the vesting of shares of Common Stock subject to a Stock Award may be based solely on the passage of time or on any other criteria, including without limitation, the
performance of the Participant, deemed appropriate by the Board or Committee. 
 6.6 Acceleration of Exercisability and
Vesting. The Board shall have the power to accelerate the time at which a Stock Award may first be exercised or the time during which a Stock Award or any part thereof will vest in accordance with the Plan, notwithstanding the provisions in the
Stock Award stating the time at which it may first be exercised or the time during which it will vest. 
 6.7 Terms of
Repurchase Options. The terms of any repurchase option in favor of the Company with respect to shares of Common Stock issuable pursuant to a Stock Award shall be specified in the applicable Stock Award Agreement. The price per share of Common
Stock at which such repurchase option may be exercised may be either: (i) the Fair Market Value of the shares of Common Stock on the date of the termination of the applicable Participant’s Continuous Service; or (ii) the lower of
(a) the Fair Market Value of the shares of Common Stock on the date of repurchase and (b) the original purchase price per share of Common Stock paid by the applicable Participant. 

  
 3 

 7. OPTIONS. 
 7.1 Stock Award Agreements for Options. Each Stock Award Agreement for an Option shall be in such form and shall contain such terms and conditions as the Board or Committee shall deem appropriate.
The terms and conditions of such Stock Award Agreements may change from time to time, and the terms and conditions of Stock Award Agreements for separate Options need not be identical; provided, however, that each Stock Award Agreement
for an Option shall include (through incorporation of provisions hereof by reference in the Stock Award Agreement or otherwise) the substance of the provisions set forth in this Section 7. 

7.2 Designation. All Options shall be separately designated Incentive Stock Options or Nonstatutory Stock Options at the time of
grant, and, if certificates are issued, a separate certificate or certificates shall be issued for shares of Common Stock purchased on exercise of each type of Option. 
 7.3 Term. Subject to the provisions of Section 5.4 above, no Option shall be exercisable after the expiration of ten (10) years from the date it was granted. 

7.4 Consideration. 
 (a) The purchase price of Common Stock acquired pursuant to an Option shall be paid, to the extent permitted by applicable statutes and regulations, either: (i) in cash at the time the Option
is exercised; or (ii) at the discretion of the Board at the time of the grant of the Option (or subsequently in the case of a Nonstatutory Stock Option), (a) by delivery to the Company of other Common Stock at the time the Option is
exercised, (b) according to a deferred payment or other similar arrangement with the Participant or (c) in any other form of legal consideration that may be acceptable to the Board. 

(b) Notwithstanding Section 7.4(a) above: (i) unless otherwise specifically provided in the Option, the purchase price
of Common Stock acquired pursuant to an Option that is paid by delivery to the Company of other Common Stock acquired, directly or indirectly, from the Company, shall be paid only by shares of the Common Stock of the Company that have been held for
more than six (6) months (or such longer or shorter period of time required to avoid a charge to earnings for financial accounting purposes); and (ii) in the case of any deferred payment arrangement, interest shall be compounded at least
annually and shall be charged at the minimum rate of interest necessary to avoid (a) the treatment as interest, under any applicable provisions of the Code, of any amounts other than amounts stated to be interest under the deferred payment
arrangement and (b) the treatment of the Option as a variable award for financial accounting purposes. 
 7.5 Early
Exercise. An Option may include a provision whereby the Participant may elect, at any time before the Participant’s Continuous Service terminates, to exercise the Option as to any part or all of the shares of Common Stock subject to the
Option prior to the full vesting of such shares of Common Stock. Subject to Section 6.7 above, any unvested shares of Common Stock so purchased may be subject to a repurchase option in favor of the Company or to any other restriction the Board
determines to be appropriate. 

  
 4 

 7.6 Termination of Continuous Service. 

(a) Termination Other Than for Cause or As a Result of Death or Disability. In the event that a Participant’s Continuous
Service terminates other than for Cause or as a result of the Participant’s Disability or death, the Participant may exercise his or her Option (to the extent that the Participant was entitled to exercise such Option as of the date of
termination) at any time within the period (the “Post-Termination Exercise Period”) ending on the earlier of: (i) the expiration of the term of the Option as set forth in the applicable Stock Award Agreement; or
(ii) the date three (3) months following the termination of the Participant’s Continuous Service (or such longer or shorter period specified in the applicable Stock Award Agreement, which period shall not be less than thirty
(30) days). If, after the termination of such Participant’s Continuous Service, such Participant does not exercise his or her Option within such Post-Termination Exercise Period, the Option shall terminate. 

(b) Termination for Cause. In the event a Participant’s Continuous Service is terminated for Cause, the Option shall
terminate upon the termination date of such Participant’s Continuous Service, and the Participant shall be prohibited from exercising his or her Option as of the time of such termination. 

(c) Termination As a Result of Disability. In the event that a Participant’s Continuous Service terminates as a result of the
Participant’s Disability, the Participant may exercise his or her Option (to the extent that the Participant was entitled to exercise such Option as of the date of termination), at any time during the Post-Termination Exercise Period ending on
the earlier of: (i) the expiration of the term of the Option as set forth in the Stock Award Agreement; or (ii) the date twelve (12) months following such termination of Continuous Service (or such longer or shorter period specified
in the Stock Award Agreement, which period shall not be less than six (6) months). If, after termination of Continuous Service, the Participant does not exercise his or her Option within such Post-Termination Exercise Period, the Option shall
terminate. 
 (d) Termination As a Result of Death. In the event that a Participant’s Continuous Service terminates
as a result of the Participant’s death or a Participant dies within any applicable Post-Termination Exercise Period, then such Participant’s Option may be exercised (to the extent the Participant was entitled to exercise such Option as of
the date of death) by the Participant’s estate, by a Person who acquired the right to exercise the Option by bequest or inheritance or by a Person designated to exercise the Option upon the Participant’s death pursuant to
Section 7.7(b) or 7.8(b) below, at any time during the Post-Termination Exercise Period ending on the earlier of: (i) the expiration of the term of the Option as set forth in the Stock Award Agreement; or (ii) the date eighteen
(18) months following such termination of Continuous Service (or such longer or shorter period specified in the Stock Award Agreement, which period shall not be less than six (6) months). If, after termination of Continuous Service, the
Participant does not exercise his or her Option within such Post-Termination Exercise Period, the Option shall terminate. 

  
 5 

 7.7 Special Provisions for Incentive Stock Options. 

(a) Exercise Price. Subject to the provisions of Section 5.4 above, the exercise price of each Incentive Stock Option shall
be not less than one hundred percent (100%) of the Fair Market Value of the Common Stock subject to the Incentive Stock Option on the date the Incentive Stock Option is granted. Notwithstanding the foregoing, an Incentive Stock Option may be
granted with an exercise price lower than that set forth in the preceding sentence if such Incentive Stock Option is granted pursuant to an assumption or substitution for another option in a manner satisfying the provisions of Section 424(a) of
the Code. 
 (b) Transferability. An Incentive Stock Option shall not be transferable except by will or by the laws of
descent and distribution and shall be exercisable during the lifetime of the Participant only by the Participant. Notwithstanding the foregoing, a Participant may, by delivering written notice to the Company in a form satisfactory to the Company,
designate a third party who, in the event of the death of such Participant, shall thereafter be entitled to exercise such Participant’s Incentive Stock Option. 
 (c) $100,000 Limitation. To the extent that the aggregate Fair Market Value (determined at the time of grant) of Common Stock with respect to which Incentive Stock Options are exercisable for the
first time by any Participant during any calendar year under all plans of the Company and its Affiliates exceeds $100,000, the Incentive Stock Options or the portions thereof that exceed such limit (according to the order in which they were granted)
shall be treated as Nonstatutory Stock Options, notwithstanding any contrary provision of the applicable Stock Award Agreement(s). 
 7.8 Special Provisions for Nonstatutory Stock Options. 
 (a) Exercise
Price. Subject to the provisions of Section 5.4 above, the exercise price of each Nonstatutory Stock Option shall be not less than eighty-five percent (85%) of the Fair Market Value of the Common Stock subject to the Nonstatutory Stock
Option on the date the Nonstatutory Stock Option is granted. Notwithstanding the foregoing, a Nonstatutory Stock Option may be granted with an exercise price lower than that set forth in the preceding sentence if such Nonstatutory Stock Option is
granted pursuant to an assumption or substitution for another option in a manner satisfying the provisions of Section 424(a) of the Code. 
 (b) Transferability. A Nonstatutory Stock Option shall not be transferable except by will or by the laws of descent and distribution and, to the extent provided in the Stock Award Agreement at the
time of the grant of the Nonstatutory Stock Option, and shall be exercisable during the lifetime of the Participant only by the Participant. If a Nonstatutory Stock Option does not provide for transferability, then such Nonstatutory Stock Option
shall not be transferable except by will or by the laws of descent and distribution and shall be exercisable during the lifetime of the Participant only by the Participant. Notwithstanding the foregoing, a Participant may, by delivering written
notice to the Company in a form satisfactory to the Company, designate a third party who, in the event of the death of such Participant, shall thereafter be entitled to exercise such Participant’s Nonstatutory Stock Option. 

  
 6 

 8. STOCK BONUSES. 
 8.1 Stock Award Agreements for Stock Bonuses. Each Stock Award Agreement for a stock bonus shall be in such form and shall contain such terms and conditions as the Board or Committee shall deem
appropriate. The terms and conditions of such Stock Award Agreements may change from time to time, and the terms and conditions of Stock Award Agreements for separate stock bonuses need not be identical; provided, however, that each
Stock Award Agreement for a stock bonus shall include (through incorporation of provisions hereof by reference in the Stock Award Agreement or otherwise) the substance of the provisions set forth in this Section 8. 

8.2 Consideration. A stock bonus may be awarded in consideration for past services actually rendered to the Company or an
Affiliate for its benefit. 
 8.3 Termination of Participant’s Continuous Service. In the event that a
Participant’s Continuous Service terminates, the Company may reacquire, for no consideration, any or all of the shares of Common Stock held by the Participant that have not vested as of the date of termination under the terms of the Stock Award
Agreement for the stock bonus. 
 8.4 Transferability. Rights to acquire shares of Common Stock under the Stock Award
Agreement for a stock bonus shall not be transferable except by will or by the laws of descent and distribution and shall be exercisable during the lifetime of the Participant only by the Participant. 

9. RESTRICTED STOCK AWARDS. 
 9.1 Stock Award Agreements for Restricted Stock Awards. Each Stock Award Agreement for a Restricted Stock Award shall be in such form and shall contain such terms and conditions as the Board or
Committee shall deem appropriate. The terms and conditions of such Stock Award Agreements may change from time to time, and the terms and conditions of Stock Award Agreements for separate Restricted Stock Awards need not be identical;
provided, however, that each Stock Award Agreement for a Restricted Stock Award shall include (through incorporation of provisions hereof by reference in the Stock Award Agreement or otherwise) the substance of the provisions set forth
in this Section 9. 
 9.2 Purchase Price. At the time of grant of a Restricted Stock Award, the Board or Committee
will determine the price to be paid by the Participant for each share of Common Stock subject to such Restricted Stock Award. Subject to the provisions of Section 5.4 above, the purchase price of Restricted Stock Awards shall not be less than
eighty-five percent (85%) of the Fair Market Value of the Common Stock on the date such Restricted Stock Award is made or at the time the purchase is consummated. A Restricted Stock Award may be awarded as a stock bonus (i.e., with no cash
purchase price to be paid) to the extent permissible under applicable law. 
 9.3 Consideration. At the time of the grant
of a Restricted Stock Award, the Board will determine the consideration permissible for the payment of the purchase price of the Restricted Stock Award. The purchase price of Common Stock acquired pursuant to the Stock Award Agreement for the
Restricted Stock Award shall be paid either: (i) in cash at the time of 

  
 7 

 
purchase; (ii) at the discretion of the Board, according to a deferred payment or other similar arrangement with the Participant; (iii) by services rendered or to be rendered to the
Company; or (iv) in any other form of legal consideration that may be acceptable to the Board in its discretion. 
 9.4
Termination of Participant’s Continuous Service. Subject to Section 6.7, in the event that a Participant’s Continuous Service terminates, the Company may repurchase or otherwise reacquire any or all of the shares of Common Stock
held by the Participant that have not vested as of the date of termination under the terms of the Stock Award Agreement for such Participant’s Restricted Stock Award. 
 9.5 Transferability. Rights to acquire shares of Common Stock under the Stock Award Agreement for a Restricted Stock Award shall not be transferable except by will or by the laws of descent and
distribution and shall be exercisable during the lifetime of the Participant only by the Participant. 
 10. ADJUSTMENTS UPON CHANGES
IN STOCK. 
 10.1 Capitalization Adjustments. If any change is made in, or any event occurs with respect to, the
Common Stock of the Company without the receipt of consideration by the Company (through merger, consolidation, reorganization, recapitalization, reincorporation, stock dividend, dividend in property other than cash, stock split, liquidating
dividend, combination of shares, exchange of shares, change in corporate structure or other transaction (each a “Capitalization Adjustment”)), the Plan will be appropriately adjusted in the class and maximum number of
securities subject to the Plan pursuant to Section 4.1, and the outstanding Stock Awards will be appropriately adjusted in the class and number of securities and price per share of Common Stock subject to such outstanding Stock Awards;
provided, however, that the conversion of any convertible securities of the Company shall not be treated as a transaction “without receipt of consideration” by the Company and shall not give rise to a Capitalization
Adjustment pursuant to this Section 10.1. The Board or Committee shall make such adjustments, which shall be final, binding and conclusive. 
 10.2 Dissolution or Liquidation. In the event of a dissolution or liquidation of the Company, all outstanding Stock Awards shall terminate immediately prior to the completion of such dissolution or
liquidation, and shares of Common Stock subject to any repurchase option in favor of the Company may be repurchased by the Company, regardless of whether or not the applicable Participant’s Continuous Service has terminated. 

10.3 Corporate Transaction. 
 (a) In the event of a Corporate Transaction, any surviving corporation or acquiring corporation may (but need not) assume or continue any or all Stock Awards outstanding under the Plan or may (but
need not) substitute similar stock awards for Stock Awards outstanding under the Plan (including an award to acquire the same consideration paid to the stockholders or the Company, as the case may be, pursuant to the Corporate Transaction), and any
reacquisition or repurchase rights held by the Company in respect of Common Stock issued pursuant to Stock Awards may be assigned by the Company to the 

  
 8 

 
successor of the Company or to the acquiring corporation (or such successor’s or acquiring corporation’s parent company), if any, in connection with such Corporate Transaction. In the
event any surviving corporation or acquiring corporation elects to assume or continue any or all Stock Awards outstanding under the Plan, such Stock Awards shall remain in effect in accordance with the terms of this Plan and the applicable Stock
Award Agreements, but shall thereafter represent the right to receive (upon exercise thereof in accordance with the terms of such Stock Awards, if applicable) for each share of Common Stock underlying each such Stock Award such cash, securities or
other property that would have been received by the applicable Participant had such Participant exercised such Stock Award immediately prior to the effective time of the Corporate Transaction. 

(b) In the event that, in connection with a Corporate Transaction, any surviving corporation or acquiring corporation does not
assume or continue any or all such outstanding Stock Awards or substitute similar stock awards for such outstanding Stock Awards, then with respect to Stock Awards that have not been assumed, continued or substituted, such Stock Awards shall
terminate if not exercised (if applicable) at or prior to the effective time of such Corporate Transaction, and any reacquisition or repurchase rights held by the Company with respect to such Stock Awards held by Participants whose Continuous
Service has not terminated shall (contingent upon the effectiveness of the Corporate Transaction) lapse. 
 10.4 Change in
Control. A Stock Award held by any Participant whose Continuous Service has not terminated prior to the effective time of a Change in Control may be subject to additional acceleration of vesting and exercisability upon or after such Change in
Control as may be provided in the Stock Award Agreement for such Stock Award; provided, however, that in the absence of any such provision in the Stock Award Agreement for such Stock Award, no such acceleration shall occur. 

11. TERMINATION, SUSPENSION AND AMENDMENT. 
 11.1 Termination or Suspension of the Plan. The Board may terminate or suspend the Plan at any time. Unless sooner terminated, the Plan shall terminate on the day before the tenth
(10th) anniversary of the date the Plan is adopted by the Board or approved by the stockholders of the Company, whichever is earlier. No Stock Awards may be granted under the Plan while the Plan is suspended or after it is terminated.

 11.2 Amendment of the Plan and Stock Awards. Subject to Section 11.3 below, the Board may, from time to time,
amend the Plan or any Stock Award in any manner it deems appropriate or necessary. Notwithstanding the foregoing, except as expressly provided elsewhere in the Plan, no amendment to the Plan shall be effective unless approved by the stockholders of
the Company to the extent stockholder approval is necessary to satisfy the requirements of Section 422 of the Code. 

11.3 No Impairment. No termination or suspension of the Plan or amendment of the Plan or any Stock Award shall impair the rights
of a Participant with respect to any outstanding Stock Award, unless the Company receives the written consent of such Participant. 

  
 9 

 12. MISCELLANEOUS. 
 12.1 Compliance with Laws. 
 (a) This Plan and the obligations of
the Company with respect to any Stock Awards granted hereunder shall be subject to all applicable federal and state securities laws. If, after reasonable efforts, the Company is unable to obtain from any applicable regulatory commission or agency
the authority that legal counsel for the Company deems necessary for the lawful issuance and sale of Common Stock pursuant to such Stock Awards, then the Company shall be relieved from any liability for failure to issue and sell Common Stock in
connection with such Stock Awards unless and until such authority is obtained. 
 (b) To facilitate the grant of any
Stock Award, the Committee may impose special terms for Stock Awards granted to Participants who are foreign nationals or who are employed by the Company or any Affiliate outside of the United States as the Board or Committee may consider necessary
or appropriate to accommodate differences in local laws, tax policies or customs. 
 12.2 Severability. If one or more
provisions of this Plan are held to be unenforceable under applicable law, such provision shall be excluded from this Plan and the balance of the Plan shall be interpreted as if such provision were so excluded and shall be enforceable in accordance
with its terms. 
 12.3 Governing Law. The law of the State of Delaware shall govern all questions concerning the
construction, validity and interpretation of this Plan, without regard to such state’s conflict of laws rules. 

*        *        * 

  
 10 

 APPENDIX A 
 DEFINITIONS 
 “Affiliate” means any parent
corporation or subsidiary corporation of the Company, whether now or hereafter existing, as those terms are defined in Sections 424(e) and (f), respectively, of the Code. 
 “Board” means the Board of Directors of the Company. 

“Cause” means, with respect to a particular Participant (unless otherwise provided in any employment agreement
between the Company and such Participant), the occurrence of any of the following: (i) such Participant’s conviction of any felony or any crime involving fraud; (ii) such Participant’s participation (whether by affirmative act or
omission) in a fraud or felonious act against the Company and/or its Affiliates; (iii) such Participant’s violation of any statutory or fiduciary duty, or duty of loyalty owed to the Company and/or its Affiliates and which has a material
adverse effect on the Company and/or its Affiliates; (iv) such Participant’s violation of state or federal law in connection with such Participant’s performance of such Participant’s job; (v) breach of any material term of
any contract between such Participant and the Company and/or its Affiliates; and (vi) such Participant’s violation of any material Company policy; provided, however, that the final determination that a termination is for
Cause shall be made by the Board or Committee, as applicable, in its sole and exclusive judgment and discretion. 

“Change in Control” means any Corporate Transaction or the occurrence, in any single transaction or in any series
of related transactions not approved by the Board, of any Person becoming the Owner, directly or indirectly, of securities of the Company representing more than fifty percent (50%) of the combined voting power of the Company’s
then-outstanding securities; provided, however, that notwithstanding the foregoing or any other provision of this Plan, the definition of Change in Control (or any analogous term) in an individual written agreement between the Company
or any Affiliate and the Participant shall supersede the foregoing definition with respect to Stock Awards subject to such agreement (it being understood, however, that if no definition of Change in Control or any analogous term is set forth in such
an individual written agreement, the foregoing definition shall apply). 
 “Code” means the Internal
Revenue Code of 1986, as amended. 
 “Committee” means a committee of two (2) or more members of
the Board appointed by the Board in accordance with Section 3.2 of the Plan. 
 “Common Stock”
means the Company’s common stock. 
 “Company” means Aratana Therapeutics, Inc., a Delaware
corporation. 
 “Consultant” means any person, including an advisor, engaged by the Company or an
Affiliate to render consulting or advisory services and who is compensated for such services; provided, however, that the term “Consultant” shall not include Directors who are not compensated by the Company for their services
as Directors, and the payment of a fee by the Company for services which the Board determines in its sole discretion are services as a Director shall not cause a Director to be considered a “Consultant” for purposes of the Plan.

  
 A-1

 “Continuous Service” means that the Participant’s service with
the Company or an Affiliate, whether as an Employee, Director or Consultant, is not interrupted or terminated. A change in the capacity in which the Participant renders service to the Company or an Affiliate as an Employee, Consultant or Director or
a change in the entity for which the Participant renders such service, provided that there is no interruption or termination of the Participant’s service with the Company or an Affiliate, shall not terminate a Participant’s Continuous
Service. For example, a change in status from an Employee of the Company to a Consultant of an Affiliate, or to a Director shall not constitute an interruption of Continuous Service. The Board, Committee or any authorized Officer of the Company, in
that party’s sole discretion, may determine whether Continuous Service shall be considered interrupted in the case of any leave of absence approved by that party, including sick leave, military leave or any other personal leave. Notwithstanding
the foregoing, a leave of absence shall be treated as Continuous Service for purposes of vesting in a Stock Award only to such extent as may be provided in the Company’s leave of absence policy or in the written terms of the Participant’s
leave of absence. 
 “Corporate Transaction” means the occurrence, in a single transaction or in a
series of related transactions, of any one or more of the following events: 
 (a) there is consummated a merger,
consolidation or similar transaction involving (directly or indirectly) the Company if, immediately after the consummation of such merger, consolidation or similar transaction, the stockholders of the Company immediately prior thereto do not Own,
directly or indirectly, either: (i) outstanding voting securities representing more than fifty percent (50%) of the combined outstanding voting power of the surviving Entity in such merger, consolidation or similar transaction; or
(ii) more than fifty percent (50%) of the combined outstanding voting power of the parent of the surviving Entity in such merger, consolidation or similar transaction; 

(b) the stockholders of the Company approve or the Board approves a plan of complete dissolution or liquidation of the Company, or
a complete dissolution or liquidation of the Company shall otherwise occur; or 
 (c) there is consummated a sale of all
or substantially all of the consolidated assets of the Company and its Subsidiaries, other than a sale of all or substantially all of the consolidated assets of the Company and its Subsidiaries to an Entity more than fifty percent (50%) of the
combined voting power of the voting securities of which Entity is Owned by stockholders of the Company in substantially the same proportion as their Ownership of the Company immediately prior to such sale. 

The term “Corporate Transaction” shall not include a sale of assets, merger or other transaction effected exclusively for the
purpose of changing the domicile of the Company. 
 “Director” means a member of the Board. 

“Disability” means the inability of a person (unless otherwise provided in any employment agreement between the
Company and such person), in the opinion of a qualified physician acceptable to the Company, to perform the duties of that person’s position with the Company or an Affiliate because of the sickness or injury of the person. 

  
 A-2

 “Employee” means any person employed by the Company or an Affiliate;
provided, however, that service as a Director, or payment of a fee by the Company for services which the Board determines in its sole discretion are services as a Director or as a member of the Board of Directors of an Affiliate, shall
not be sufficient to constitute “employment” by the Company or such Affiliate. 
 “Entity”
means any corporation (including any non-profit corporation), general partnership, limited partnership, limited liability partnership, joint venture, estate, trust, company (including any limited liability company or joint stock company),
firm or other enterprise, association, organization or entity. 
 “Fair Market Value” means, as of any
date, the value of the Common Stock determined by the Board in good faith. 
 “Incentive Stock Option”
means an option to purchase shares of Common Stock that is intended to qualify as an “incentive stock option” within the meaning of Section 422 of the Code and the regulations promulgated thereunder. 

“Nonstatutory Stock Option” means an option to purchase shares of Common Stock that is not intended to qualify as
an Incentive Stock Option. 
 “Officer” means any person designated by the Company as an officer.

 “Option” means an Incentive Stock Option or a Nonstatutory Stock Option granted pursuant to the Plan.

 A Person shall be deemed to “Own”, to have “Owned”, to be the
“Owner” of, or to have acquired “Ownership” of securities if such Person, directly or indirectly, through any contract, arrangement, understanding, relationship or otherwise, has or shares voting
power, which includes the power to vote or to direct the voting, with respect to such securities. 

“Participant” means a person to whom a Stock Award is granted pursuant to the Plan or, if applicable, such other
person who holds an outstanding Stock Award. 
 “Person” means any natural person or Entity. 

“Plan” means this 2010 Equity Incentive Plan. 

“Restricted Stock Award” means an award of shares of Common Stock, which is granted pursuant to the terms and
conditions of Section 9 of the Plan. 
 “Securities Act” means the Securities Act of 1933, as
amended. 
 “Stock Award” means any right granted under the Plan, including an Option, a Restricted
Stock Award or a stock bonus. 

  
 A-3

 “Stock Award Agreement” means a written agreement between the
Company and a Participant evidencing the terms and conditions of an individual Stock Award. Each Stock Award Agreement shall be subject to the terms and conditions of the Plan. 

“Ten Percent Stockholder” means a person who Owns (or is deemed to Own pursuant to Section 424(d) of the
Code) stock possessing more than ten percent (10%) of the total combined voting power of all classes of stock of the Company or of any of its Affiliates. 

  
 A-4

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00214-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00214-of-00352.parquet"}]]