Today’s edition of CDC’s Morbidity and Mortality Weekly Report includes a report about rabies exposure in an animal shelter.

The situation occurred in March 2010, when a stray dog taken to a North Dakota animal shelter was diagnosed with rabies. An investigation was undertaken to look into human and animal exposure.

  • Potential exposure was investigated in 32 people. Of these, 21 were determined to fit criteria for requiring post-exposure prophylaxis. This included nine shelter employees and one volunteer.
  • Twenty-five dogs at the shelter were considered exposed. According to the report "In accordance with 2009 Compendium of Animal Rabies Prevention and Control guidance (1), the 25 dogs in the shelter with the rabid dog were euthanized." That’s a somewhat misleading statement. Immediate euthanasia is not the only recommendation in this kind of situation, it’s just one of the options. In a dog that has not been vaccinated (or whose vaccination status is unknown), euthanasia OR six months of strict quarantine is indicated. The decision to euthanize was probably a logistical one, not being able or wanting to quarantine this many dogs for such a long period of time. It’s a reasonable decision given limited isolation capacity (and budget).
  • Twenty-five other unvaccinated dogs that were adopted or claimed by their owners were also exposed. (Presumably, these were dogs that had contact with the infected dog, then went to homes before the rabid dog was diagnosed). Of these, 11 were euthanized, 13 were quarantined for 6 months at home, and one was ‘unintentionally killed‘ (whatever that means). All euthanized dogs were tested and were negative for rabies.

A few issues were raised in the report:

Rabies vaccination of shelter personnel: "In addition, preexposure prophylaxis for animal shelter workers or other persons whose activities bring them into frequent contact with potentially infected animals should be considered, in accordance with Advisory Committee on Immunization Practices recommendations (6)" This is a complex issue. It would be ideal for all shelter employees to be vaccinated, and I’d love to see that done. The problem is actually getting it done. Shelters often have many employees and volunteers, and a very transient worker population. Getting all these people vaccinated is tough. Vaccinating short term, part time and temporary employees is tough enough, let alone volunteers. Cost is also an issue. Is it realistic to make people volunteering or earning low wages to pay the expensive cost of vaccination? Can shelters afford to pay for vaccination? What happens if someone doesn’t want to be vaccinated? This is an ongoing issue in shelter medicine and one where there is no clear consensus. Shelter personnel clearly fit standard recommendations as being a group in which vaccination should be considered, but it’s easier said than done.

Vaccination of animals: "First, all domestic animals should be vaccinated against rabies, in accordance with guidelines (1,8)." This is another issue that is very good in principle but tougher in practice. Rabies vaccination must be done by a veterinarian in most regions, and most shelters do not have a resident veterinarian. Getting animals vaccinated promptly after admission can be difficult. Ideally, shelters would have better and closer relationships with veterinarians, but it’s quite variable (and an area that needs improvement). Vaccination would also not help much in some situations, since it does not result in immediate protection. Dogs that are vaccinated are not considered protected for 28 days. Therefore, even if they were vaccinated at arrival, some of the dogs in this situation would still be considered unprotected. Nonetheless, I don’t want to dismiss the role of vaccination, and I think shelters need to significantly increase rabies vaccination rates. It’s not a simple problem, however. 

Contact in the shelter: "Second, animals without documentation of vaccination against rabies should be kept separate from the public, wildlife, and other animals to prevent transmission of the virus (5,8)." Another "good in principle, but have you ever been to a shelter?" statement. Shelters don’t have lots of space. Having enough room to properly separate incoming, sick, and adoption animals is hard enough. Having to separate all those groups into rabies-vaccinated and non-vaccinated, or individually isolate animals, is going to be impossible logistically in most facilities. The concept of cohorting animals of different risks is excellent and can be improved on, it’s just not possible to isolate all animals that are unvaccinated or of unknown vaccination status (i.e. almost every animal coming into a shelter). This is particularly true since they are not considered protected until 28 days after vaccination.

Infection control practices: "In this case, 36 dogs had to be euthanized because employees and volunteers might not have consistently followed the shelter’s policy of preventing muzzle-to-muzzle contact between dogs." Compliance with infection control practices is an issue, and it could be improved. It’s an area we’re working on now.

Definition of contact: In this particular situation, a very broad definition of contact (that may result in exposure) was used. "Although the shelter’s animal handling policies likely minimized contact among dogs, muzzle-to-muzzle contact could not be ruled out; therefore, BOAH and NDDoH recommended that all dogs present in the shelter from March 9–20 be euthanized."  It’s quite unlikely that any of these other dogs were truly exposed if this is the only kind of contact they may have had with the rabid dog. Balancing public health and animal welfare is difficult. Certainly, you need to err on the side of caution, but how far do you go? Quarantine would have been ideal because of the extremely low likelihood of exposure, however if it’s not practical (or feasible or affordable) in a shelter situation, euthanasia may be the only option.

This was a bad situation but it’s not surprising, nor will it be the last time it happens. A single rabid dog led to the euthanasia of 36 other dogs, and expensive (and probably stressful) treatment of 21 people. Shelter management can be improved to reduce the risk of this happening, but there’s no way to absolutely prevent it.

The full story can be found by clicking here.

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