Dead raccoons have gotten a lot of attention in Toronto lately, for various reasons. Many urban areas have abundant raccoon populations, and whenever there are a lot of animals (especially of the same species) living in a relatively small area, there’s greater risk for disease outbreaks. A distemper outbreak is playing a role (maybe a big role) in the latest rash of dead raccoons being found across the Toronto area. That’s bad news for the raccoons, and unpleasant for the people who who find them, not to mention the overworked animal control agencies that get called to pick up the dead raccoons, while also trying to attend to sick and injured animals of all species.
Beyond the ick factor of finding these dead raccoons, there’s fear of infectious disease exposure, particularly for dogs, from raccoon carcasses and sick raccoons. (And let’s not forget about cats either… risks to cats usually get ignored in these situations).
What are the real disease risks from all these dead raccoons?
Overall, the risks are pretty limited.
Distemper in raccoons is caused by canine distemper virus (CDV), the virus that causes (unsurprisingly) distemper in dogs. Distemper can cause serious, including fatal, disease in dogs, just like it does in raccoons.
So are dogs at risk from sick and dead raccoons?
Yes, dogs can get distemper from raccoons, but the good news is that we have very effective vaccines against distemper in dogs. Distemper is included in the standard “core” vaccines that all dogs should get regularly. We typically start vaccinating puppies at 8 weeks of age and vaccinate them monthly until 16-20 weeks of age. At that point, we’re pretty confident they will be able to respond to the vaccine properly, so we normally then vaccinate a year later, then every 3 years. Distemper is extremely rare in properly vaccinated dogs. Even a dog that is overdue for vaccines is probably at very low risk of infection is they were properly vaccinated as a puppy.
How would a dog get distemper from a raccoon?
Most likely, it would occur when an unvaccinated (or under-vaccinated) dog has direct contact with an infected raccoon. Although the virus is excreted in respiratory secretions and feces which can contaminate the environemnt, most of the risk probably comes from direct contact with the animal. Survival of CDV in the envionment hasn’t been well studied in field situations, but it probably only survives for hours or at most a few days. If there’s sunlight, dry periods and temperature swings, that helps inactivate the virus faster. So while we can’t dismiss the risk from indirect contact, I’m mostly worried about a dog tangling directly with an infected raccoon, which happens commonly enough even when the raccoon isn’t sick or behaving abnormally.
What’s the risk from raccoon carcasses?
The risk of distemper exposure from raccoon carcasses is probably not much. While the carcasses are unsightly, any virus on the outside of the body would die fairly quickly. The longer the raccoon has been dead, the lower the risk, so delays removing dead raccoons create more ick than disease risk.
It’s still best to get dispose of carcasses (of any kind) as soon as is reasonable. Beyond distemper, there are other potential general infectious disease risks from carcasses, but overall the risk is low, and the risk of distemper transmission to dogs is very low.
That said, why tempt fate and have a dog potentially exposed to anything from a raccoon carcass? Regular readers will have seen various pictures of our new puppy, Ozzie. It’s looking like he’s (unfortunately) going to be one of those dogs that likes to roll in disgusting things. So, job #1 is keeping him from away from animal carcasses. If he did roll on a raccoon carcass, I’d be more concerned about the smell than a disease, but I’d still give him a bath (while trying not to contaminate myself in the process).
Raccoons with distemper can act strangely. Do we have to worry about rabies?
Yes and no. We’re always concerned about rabies. However, we don’t have raccoon variant rabies in Toronto (as far as we know). There’s pretty good surveillance in the region, and it seems not to have made its way to Toronto after its last incursion into Ontario in 2015, when raccoon rabies was focused a bit further west in the Hamilton area. (In the last two years the only cases of raccoon rabies in Ontario were detected in skunks in the Niagara region. Check out the interactive Ontario rabies case map for the latest surveillance and case info.)
At this point, the vast majority of abnormally-behaving raccoons in Toronto will have distemper. But, we can never completely dismiss the potential for rabies, either because raccoon rabies has sneaked into the city, or a raccoon was infected by another rabies virus strain (e.g. from a bat). Therefore, it’s important to keep people and animals away from raccoons – even those that look normal, but especially those that are acting strangely.
The take-home messages are pretty simple:
- Keep pets under control and away from wildlife, being particularly strict with unvaccinated and under-vaccinated dogs.
- Make sure dogs are vaccinated.
That’s about it. With some common sense and basic veterinary care, we can relax about the canine implications of distemper in raccoons.