Each year in the United States, approximately 6,000 cases of rabies are documented in animals, primarily in the major wildlife reservoir species (ie, raccoons, bats, skunks, and foxes). These confirmed cases are invariably associated with 1 or more human and animal exposures to rabies. In addition, many domestic animals come into contact with sick wildlife or other animals that cannot be captured for rabies diagnostic testing and, depending on the geographic location and species of animal involved, may be considered potentially exposed to rabies. As a result, thousands of dogs and cats are known to be exposed or are potentially exposed to rabies each year in the United States.
Regulations have been developed to minimize the public health risks that dogs and cats exposed or potentially exposed to rabies and potentially incubating the virus may pose. These regulations vary, depending on locality, but most public health officials refer to or rely on the Compendium of Animal Rabies Prevention and Control1 for guidance in these situations.
According to the current version of the compendium, dogs and cats with current rabies vaccination status that have been exposed to an animal confirmed or suspected to be rabid should immediately receive a rabies booster vaccination and be observed for 45 days, most often, as allowed by jurisdictional authorities, under the owner's supervision with no contact restrictions. The recommendation for dogs and cats that have never been vaccinated against rabies and that have been exposed to a rabid animal is euthanasia or quarantine for 6 months in a specialized facility.
In contrast, the compendium guidelines are less clear when it comes to recommendations for dogs and cats overdue for a booster vaccination (ie, dogs and cats with out-of-date rabies vaccination status), suggesting that these animals be evaluated on a case-by-case basis that takes into account the severity of the exposure, time since the last rabies vaccination, number of rabies vaccinations received previously, current health status of the animal, and local rabies epidemiology.1 Unfortunately, this recommendation for a case-by-case risk assessment coupled with concerns for public safety, a fear of liability, and the lack of published clinical data regarding response to rabies vaccination in dogs and cats with an out-of-date rabies vaccination status commonly leads to conservative handling of these animals. Most often, this means that public health officials consider these animals to be unvaccinated, resulting in either euthanasia or a 6-month quarantine.
The present study was designed to provide greater insight into the appropriate handling of dogs and cats with out-of-date rabies vaccination status that have been exposed to rabid animals. Specifically, the purpose of the study reported here was to compare anamnestic antibody responses of dogs and cats with current versus out-of-date rabies vaccination status.
Rainforth R, Merck, White House Station, NJ: Personal communication, 2014.
Menardi R, Merial, Duluth, Ga: Personal communication, 2014.
Proc PHREG, SAS/STAT, version 9.3, SAS Institute Inc, Cary, NC.
1. Brown CM, Conti L, Ettestad P, et al. Compendium of animal rabies prevention and control, 2011. J Am Vet Med Assoc 2011; 239: 609–617.
2. Lau E. States consider controlling rabies vaccination intervals (2011). Veterinary Information Network. Available at: news.vin.com;VINNews.aspx?articleId=19501. Accessed Apr 23, 2014.
3. Smith JS, Yager PA, Baer GM. A rapid reproducible test for determining rabies neutralizing antibody. Bull World Health Organ 1973; 48: 535–541.
4. World Organisation for Animal Health. Chapter 2.1.13. Rabies. In: OIE terrestrial manual. Paris: World Organisation for Animal Health, 2013;1–28. Available at: www.oie.int;fileadmin;Home;eng;Health_standards;tahm;2.01.13_RABIES.pdf. Accessed Jun 1, 2014.
5. Mansfield KL, Burr PD, Snodgrass R, et al. Factors affecting the serological response of dogs and cats to rabies vaccination. Vet Rec 2004; 154: 423–426.
8. Hooper DC, Morimoto K, Bette M, et al. Collaboration of antibody and inflammation in clearance of rabies virus from the central nervous system. J Virol 1998; 72: 3711–3719.