For some reason, I’ve been spending a lot more time lately discussing vaccination, so I figured I’d write about a series of vaccine issues, questions and dogmas (that are often non-evidence-based or just downright wrong).

Age for first rabies vaccine

Here in Canada at least, rabies vaccines are licensed for use in dogs and cats (and ferrets) that are 12 weeks of age or older. In Ontario, provincial regulations require rabies vaccination of dogs, cats and ferrets at this age and beyond. Yet, dogs and cats often receive their first rabies vaccine at 16 weeks of age.  That’s even what I did when I was in general practice (eons ago) before specializing.

Why do so many veterinarians wait until 16 weeks to vaccinate puppies and kittens for rabies?

  • Not sure.
  • Maybe it’s just a habit we (as a profession) have gotten into.
  • Maybe it’s because we think clients are motivated to give their pets a rabies vaccination, but less so to give other vaccines, and we want to make sure they come back for their 16+ week “core” vaccine shot (more on the timing of core vaccines in another post in this series). In that event, holding off on rabies vaccination until the final puppy/kitten vaccine might help make sure they come back.

Consider the cost of waiting.

One issue is the potential for the animal to get infected with rabies, obviously. Waiting creates a longer period of time when the pet is susceptible to rabies. What are the odds the dog/cat will be exposed to rabies and get infected in that extra one month period? Low, but it’s an avoidable delay (and consider the insatiable curiosity of many puppies and kittens which may make them more apt to “play” with certain rabies reservoir species, like bats).

The other issue, and in many ways the bigger issue, is the necessary response to a potential rabies exposure. While rabies in dogs and cats is relatively rare in Canada, potential rabies exposure via pet-vs-wildlife interactions, particularly with rabies reservoir species, is very common. If a dog or cat tangles with a wild animal and rabies can’t be ruled out through testing or other means, or if rabies is confirmed in that wild animal, that pet may be considered exposed. The post-exposure management of a dog or cat in this situation depends on the pet’s vaccination status.

The approach to rabies post-exposure management in dogs and cats in Ontario is similar to elsewhere:

Dog/cat/ferret that is unvaccinated (or received its first rabies vaccine less than 28 days before exposure):

  • If the pet gets a rabies vaccine within 7 days, the pet gets a 3 month “precautionary confinement period” (PCP)It’s not called “quarantine” in Ontario since that term has different legal connotations, but it’s essentially the same thing. See the table at the bottom of the post for details.
  • If the pet does not get a rabies vaccine within 7 days, the pet gets a 6 months precautionary confinement period.

Dog/cat/ferret that has received primary vaccination for rabies (i.e. one dose, and not yet due for a 2nd dose):

  • If the pet gets a rabies vaccine within 7 days: no formal confinement period, but a 45 day home observation period
  • If the pet does not get a rabies vaccine within 7 days: 3 month precautionary confinement period

As you can see, there’s a big difference in the management if a puppy or kitten has had even one dose of rabies vaccine prior to a rabies exposure.  A vaccinated puppy/kitten that gets a booster get a pretty easy observation period. Much stricter quarantine of a puppy/kitten is required for the precautionary confinement period, is tough to do and can have major impacts on the pet’s social and behavioural development. Sometimes pets are even euthanized because owners are unwilling or unable to manage the strict isolation. I’ve dealt with multiple situations where a puppy/kitten was potentially exposed to rabies and unvaccinated (or too recently vaccinated) when it could have been protected if it had its rabies vaccine given at 12 weeks of age. They’re horrible situations when people have to decide whether to euthanize their young pet, or isolate it from almost everyone for months, all for lack of giving one vaccine a few weeks earlier.

So, puppies and kittens should be vaccinated at 12 weeks of age, regardless of what’s happening with other vaccines.  In Ontario it’s the law, but it is an equally sound recommendation in any other region (in Canada or elsewhere) where rabies is a risk.