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United States 

Department of 

Agriculture

Animal and Plant 

Health Inspection 

Service 

Veterinary Services 

Center for Veterinary 

Biologics 

510 S. 17th Street, 

Suite 104 

Ames, IA 50010 

(515) 232-5785 

FAX (515) 232-7120 

February 24, 2005 

CENTER FOR VETERINARY BIOLOGICS NOTICE NO. 05-06 

Subject: Requirements for Addition of Leptospira bratislava in Canine Bacterins 

To: Biologics Licensees, Permittees, and Applicants 

Directors, Center for Veterinary Biologics 

I. PURPOSE 

This notice informs licensees, permittees, and applicants of current Center for Veterinary 

Biologics (CVB) policy regarding requirements for the addition of Leptospira interrogans

serovar bratislava antigen to current canine leptospira-containing bacterins. 

II. BACKGROUND 

Recent inquiries regarding the of addition of Leptospira interrogans serovar bratislava 

antigen to current canine leptospira-containing bacterins have necessitated that CVB 

establish a consistent policy on this issue and communicate that policy to the veterinary 

biologics industry. 

Although there is limited evidence that Leptospira interrogans serovar bratislava may be a 

pathogen of dogs in the United States, the information in published scientific literature is 

deemed by CVB to be insufficient to warrant addition of the L. bratislava antigen to canine 

leptospira-containing bacterins. Nearly all of the current data supporting the theory that 

L. bratislava is a significant canine pathogen in the United States are based on serology 

which is not considered to be a definitive indication of disease etiology for leptospirosis. 

Despite publications demonstrating the ability to isolate the organism from naturally and 

experimentally infected animals, only a single case of isolation from a clinically ill dog in 

the United States exists in the published literature. Until evidence acceptable to CVB is 

published in the scientific literature that establishes Leptospira interrogans serovar 

bratislava as a significant pathogen of dogs in the United States, firms will need to provide 

that evidence before inclusion of the L. bratislava antigen in licensed leptospira-containing 

bacterins will be considered. 

III. POLICY 

The following is the minimum evidence required for inclusion of the L. bratislava antigen 

in licensed leptospira-containing bacterins. 

1. Proof of disease etiology confirmed by isolation of the organism from a minimum of 10 

dogs demonstrating clinical signs consistent with leptospirosis. The animals must originate 

from outbreaks that are not epidemiologically linked. 
Center for Veterinary Biologics Notice No. 05-06 2 

2. Isolations must be conducted by a minimum of two independent laboratories. 

3. Culture identities must be confirmed in a manner acceptable to CVB. 

4. The identity of all bacteria, viruses, and other disease agents isolated from the clinically 

ill animals must be reported so that the possibility of other etiologies of the disease, or the 

possibility of synergistic infections, can be evaluated. 

5. Although no acceptable Leptospiral identification methods other than culture currently 

exist which are capable of differentiating serovars of Leptospira, such methods may be 

developed in the future (e.g., polymerase chain reaction). Such methods may be used for 

proof of disease etiology only if the test method is validated in a manner acceptable to 

CVB. If test methods other than culture are used to prove disease etiology, then a 

minimum of 25 clinically affected dogs from outbreaks that are not epidemiologically 

linked will be required. The clinically ill animals must also be evaluated for the presence 

of other possible pathogens (see 4. above). 

6. Serological evidence of infection alone will not be a sufficient indication of disease 

etiology. 

/s/ Richard E. Hill, Jr. 

Richard E. Hill, Jr. 

Director 

Center for Veterinary Biologics