Cats don't make it easy - helpful tools to assess,manage, and treat feline OA
Margaret Gruen DVM PhD DACVB1

Disclosures
Consulting or sponsored CE: Zoetis, Boehringer-Ingelheim, Elanco,
Assisi Animal HealthOA/DJD as a multidisciplinary
condition

Discussion
PointsBehaviors affected by OA pain

Why it matters: Quality of life

What’s in the future for treatment

PAIN IS MULTIDIMENSIONAL AND IS A UNIQUELYINDIVIDUAL EXPERIENCE

PHYSIOLOGIC Location
 Onset Duration
 Etiology

SENSORY Intensity
 Quality
 Pattern

BEHAVIORAL Physical activity
 Medications
 Pain behaviors
 Sleep

EMOTIONAL Mood Anxiety Well-Being

SOCIOCULTURAL
 Environment Family

McGuire DB, Comprehensive and multidimensional assessment and measurement of pain . J Pain Symptom Manage. 1992(5):312-319.

COGNITIVE
 CopingChronic pain has downstream consequences
Leads to changes reflective of:• Defensive behavior• Learned avoidance• Peripheral and central
sensitization

PainFatigue

This complicates
our managementof patients

Sleep
impairment

Rest

The cycle ofpain andstress

Changes insociability

Changesin moodmovement

Tight/tensemusclesMore Pain

Fear &Anxiety
Stresshttps://www.physiopedia.com/Considering the Stress Pain Cycle in Assessment

GuardedWeakmuscles

Decreased coping à Increased fear/avoidance
TightenedmusclesMoreinhibited
behavior

Tense

Nervous

Vigilant

OA is a multidisciplinary condition

Painmanagement

Behavior andenvironment

Primary
care/ internal
medicineWith a multidisciplinary patientPainmanagement

OADM

CKD

Behavior andenvironment

HCM

Primary
care/ internal
medicine

CKD, chronic kidney disease; DM, diabetes mellitus; HCM, hypertrophic cardiomyopathy; OA, osteoarthritis.

High overlap of DJD and CKDPrevalence and classificationof chronic kidney disease incats randomly selected fromfour age groups and in cats
recruited for degenerative
joint disease studies

Marino et al 2014

Figure 1 Prevalence of cats with chronic kidney disease (CKDpos), small kidneys, and without CKD (CKDneg) in the randomly
selected (RS) and degenerative joint disease (DJD) groups. Total prevalence (percentage) is shown above each bar. The
prevalence was calculated as the number of cats in each category out of the total number of cats in the RS and DJD groupsPrevalence of painful OA is high• Middle-aged and older cats
• 61%-92% of cats show radiographic
evidence of DJD• ~40% of all cats will have DJD andassociated pain

• More cats than are being treated

Lascelles et al. Vet Surg. 2010;39(5):535-544.
Slingerland et al. Vet J. 2011;187(3):304-309.

DJD, degenerative joint disease.

Why do we miss feline OA signs?
• Most cats do not exhibit lameness1• Frequently bilateral2,3• Tendency to be less demonstrative about pain as aprotective mechanism4• Cats compensate for severe diseasebecause they are small and agile• Radiographic changes are variable1• Cats with early disease may be very painful yet show noradiographic changes

1. Bennett D, et al. Osteoarthritis in the Cat: How common is it and how easy to recognize JFMS 2012, (14) 65-75
2. Lascelles BD et al, Feline degenerative joint disease. Vet Surg 39:2-13, 2010
3. Godfrey DR, Osteoarthritis in cats: a retrospective radiological study. J Small Anim Pract 2005 46(9); 425-429
4. Hardie EM et al, Radiographic evidence of degenerative joint disease in geriatric cats: 100 cases (1994–1997) JAVMA 2002;220:628–632

Behavior is the single best way
to assess for the presence andprogression of pain

Painful OA affects cat behavior• Changes in mobility
OAOAOA• Gait or activity• Ability to maneuver and performdaily routines• Loss of smoothness/fluidity• Changes in behavior• Decreased sociability

OA• Hiding, changes inmood/demeanor/toleranceof handlingOA

How do we
identify this cat?

How do wequantify thebehavior?

How do wemonitortreatment?

How do weidentify this cat?

How do wequantify thebehavior?

How do wemonitortreatment?

Six activities can help identify cats with OA
Percentage of cats scored as ’abnormal’

Enomoto et al. J Feline Med Surg. 2020.

Unlike dogs, these behaviors are best observed in
the home

Without owner engagement, many of these behaviors are attributed to aging

Why it matters: Quality of life
With OA:• Coping ability
decreases• Modifications needed
to ensure access

Ellis et al. J Feline Med Surg. 2013;15:219-230.

Because qualityof life is morethan justabsence ofpain…

Environment

Many impacts
on quality of life

Pain

Anxiety
Fear
Aggression

Mobility
impairment

Cognitive
declineSickness
Chronicdiseases

To understandwhat to provide,
we need tounderstand catneeds

Eating
2%

Other
1%

Grooming
8% Travel

CAT TIME BUDGET

3%

Hunting17%
Sleeping
44%

How is this alteredby chronic pain?
Resting25%

Panaman. Z Tierpsychol. 1981;56:59-73.

To understand catneeds, we need tounderstand theirhistory• Solitary hunters• Social structure is bothsolitary and community• “Time-share” resources• People are a part of cats’social structure• Use scent for communication

Solitary hunters — Midlevel predators

Cats have aflexible socialstructureTime-sharing ofresources

System of communication designed to
avoid conflictSocial interactions with people are importantActivity

Cats use scent for communication

Cats depend on us
to meet their needs• Lack of activity andenrichment could lead to avariety of health andbehavioral issues• Obesity• Inappropriate play
• Boredom/frustration• Potential for behavior problems

The importance of 3-D space• Increased 3-D space• Increased use of space and• Decreased agonistic encounters• Cats treated with effective
analgesic will resume use ofvertical space• What accommodations must be
made to preserve access?

Safe places – Ability to ‘getaway’ may be compromised

Cats with OA pain needconsistent access to safe,
comfortable spaces

How do we
identify this cat?
Owner engagement is crucial – theyknow their own cats’ behavior andnotice changes earlier
BUT, they often dismiss the changes as“slowing down” or normal aging

Learning about OA andassociated pain motivates
action among owners
Owners:• Can detect behavioral changes intheir cats
• Do not want their cats to be in pain
• Must understand that thesebehavioral changes may indicate
diseaseWhen we ask aboutpain…
• This requires a shift
in our language

Current emphasis for ‘pain’ is weighted on extreme
behaviors

Change in form of feeding behavior
Avoiding bright areas
Growling
Groaning
Eyes closed

Need to shift toawarenessLess extreme
behavioral changes
are still indicative of
painful diseasewww.CatOAchecklist.com

40

Comparisons are powerful(especially for slowly progressing conditions)Appreciation for the effects of OA pain on QoLfor cats

What wehave:Behaviors we can use to identify and monitor
OA pain
Owners motivated to provide pain control for
their cats

What are we missing?

Treatment and management

PRIMARY GOAL: RESTORE QUALITY OF LIFE

1

Lifestyle changes

2

Pharmacological intervention

3

Nonpharmacologicalintervention

Robertson, S. (2008, November 1). Osteoarthritis in cats: What we now know about recognition and treatment.Veterinary Medicine

Lifestyle changes:
Environmental
Robertson, S. (2008, November 1). Osteoarthritis in cats: What we now know about recognition and treatment. Veterinary Medicine
Epstein M,, et al. 2015 AAHA/AAFP pain management guidelines for dogs and cats. JFMS. 2015;17:251–272

Lifestyle changes:
Supportive

Robertson, S. (2008, November 1). Osteoarthritis in cats: What we now know about recognition and treatment. Veterinary Medicine
Epstein M,, et al. 2015 AAHA/AAFP pain management guidelines for dogs and cats. JFMS. 2015;17:251–272• Weight loss
• Controlled exercise• GroomingCurrent OA intervention toolbox
NSAIDS
Opioids
Alpha-2 Agonists
TricyclicantidepressantsKetamine
Gabapentinoids

Platelet-Rich Plasma
Stem cells

Nutraceuticals

Joint diets
Rehabilitation
Acupuncture

#Approved therapies

NSAIDs (meloxicam;robenacoxib)
Frunevetmab*Proven therapies

Pharmacologic
interventions:

NSAIDsDiet optimization• # None approved in the US• * Proven efficacy based on evidencebased veterinary medical literature

Remember our
multidisciplinary
patient…

OA
CKD
DM

CKD, chronic kidney disease; DM, diabetes mellitus; HCM, hypertrophic cardiomyopathy; OA, osteoarthritis.

HCMBalancing treatments and cat-human bond is criticalMany target opportunities in the periphery

Julius & Basbaum 2001. Nature 413: 203-210

Nerve Growth Factor (NGF)• During development: aids thenormal development of the nervoussystem• In the adult: primary role is pronociceptive

Target NGF dimer10.1136 /vr.104590

NGF plays an important role in OA pain

Anti-nerve growth factor monoclonal
antibodies for the control of pain indogs and cats
Masataka Enomoto,1 Patrick W Mantyh,2 Joanna Murrell,3 John F Innes,4 B Duncan X Lascelles1,5,6,7
Nerve growth factor (NGF) is essential for the survival of sensory and sympathetic neurons during development.
However, in the adult, NGF and its interaction with tropomyosin receptor kinase A receptor (TrkA) has been
VetfoundRec. to2019
Jan 5;184(1):23. (Open Access: doi: 10.1136/vr.104590)
play a critical role in nociception and nervous system plasticity in pain conditions. Thus, various
monoclonal antibody (mAb) therapies targeting this pathway have been investigated in the development of
new pharmacotherapies for chronic pain. Although none of the mAbs against NGF are yet approved for use inhumans, they look very promising for the effective control of pain. Recently, species-specific anti-NGF mAbs for

Veterinary Record: first published as 10.1136/vr.104590 on 27 October

REVIEW

Anti-NGF Strategies• Removing free NGF(Anti-NGF mAb)
• Preventing NGF
from binding to TrkA
• Prevent TrkA
activation© Innate PharmaBenefits of Monoclonal Antibodies (mAb)• Long duration of action (long half-life)• Injectable• Low risk of toxicity• Highly specific; not cross BBB©BDXLascelles, TRiP, NC State

Feline anti-NGF mAb
Proof-of-concept study1Pilot field study2• 34 cats (single site)• 126 cats (multi-site)– 23 frunevetmab; 11 placebo– 85 frunevetmab; 41 placebo• 2 injections (SQ or IV)• 1 injection (SQ)
– 7 weeks additional follow-up• Activity monitors and owner questionnaires– 4 weeks apart• Activity monitors and owner questionnaires

Both studies showed a positive effect offrunevetmab for treatment of chronic pain in cats

1 Gruen, M. E., et al. Journal of veterinary internal medicine 30.4

(2016): 1138-1148.
2 Gruen ME, Myers JAE, Lascelles BDX. Frontiers in veterinary science 8(2021).

Key takeaways• Behaviors impacted by chronic pain areimportant components of quality of life for cats
• Behavior remains the best way to assess painin cats
– These are best assessed in the home

• Owners who know what to watch for are able
to identify abnormal behavior– And are motivated to treat their cats

• New treatment options offer promise for reliefof OA pain in cats

Questions?