Rabies in vaccinated dogs and cats in the United States, 1997-2001.

OBJECTIVE: To identify cases of rabies involving vaccinated dogs and cats in the United States.

DESIGN: Retrospective data review.

SAMPLE POPULATION: 41 states that reported >or= 1 rabid dog or cat between 1997 and 2001.

PROCEDURES: States were contacted to request information on numbers of dogs and cats tested for rabies between 1997 and 2001. For animals with a history of rabies vaccination, respondents were asked to provide details of the vaccination history, age, history of exposure to rabid animals, time between exposure and onset of clinical signs, clinical signs, duration of clinical signs, and whether the animal had died or was euthanatized.

RESULTS: 21 of the 41 (51%) states agreed to participate in the study. A total of 264 rabid dogs and 840 rabid cats were identified during the study period. Thirteen (4.9%) rabid dogs and 22 (2.6%) rabid cats had a history of rabies vaccination. Of these, 2 dogs and 3 cats were classified as currently vaccinated. Overall, 6 animals (1 dog and 5 cats) had a history of receiving 2 doses of rabies vaccine in their lifetime, including 2 cats that were classified as currently vaccinated.

CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that rabies is uncommon in vaccinated dogs and cats but can occur. Veterinarians should include rabies in the differential diagnosis for any dog or cat with clinical signs compatible with rabies regardless of vaccination history. Continued surveillance is imperative to document vaccination failure and identify trends related to vaccination failure.