Distemper outbreak in California

A canine distemper outbreak has been identified in raccoons, dogs, coyotes, foxes and skunks in Los Angeles County. Local residents are being reminded to vaccinate their dogs against distemper and report any suspected signs of distemper to their veterinarian. (Keeping their pets away from wildlife should also be recommended.)

Distemper is an infection caused by a virus which is related to the virus that causes measles in people. It can cause different types of disease in dogs, raccoons and some other wild mammals, but neurological disease is often present and can appear similar to rabies.

Canine distemper cannot be transmitted to people, but, in a roundabout way, distemper outbreaks can be a public health concern.  This is because of the potential for rabies cases to be mistaken for (and dismissed as) distemper cases, leading to increased exposure of people to rabid animals.

Quite a few years ago, there was a cat with neurological problems under my parents front porch.  It was a stray cat that had been in the neighbourhood for a while, and which sometimes interacted with people. When the local authorities were contacted, the response was "Don't worry, it probably has distemper." This was probably true, and since there was no known direct contact with people (something that is difficult to really know in a social stray) testing for rabies wasn't done. However, the concern is that rabies cases will be missed, or, more concerningly, human exposure to rabid animals will be missed because of the assumption that it's really distemper.

Understanding disease patterns in an area is important when determining the likelihood of a particular disease and the appropriate response to a sick animal. At the same time, you can't get complacent and assume that trends are absolute. With an almost invariably fatal disease like rabies, you have to be careful not to overlook the rare case amongst large number of other, similarly appearing diseases. If someone has contact with an animal suspected of having distemper, the potential for rabies exposure must not be forgotten.

Image source: http://weblogs.baltimoresun.com

Distemper in raccoons and dogs

The Toronto Star had a front page article today about an ongoing distemper outbreak in raccoons, and the potential effects on dogs. Toronto's not alone, as there are distemper outbreaks underway in many different municipal regions.

Distemper is an infection caused by a virus that is related to human measles virus. It mainly affects dogs, raccoons and ferrets. It can cause intestinal, respiratory and neurological disease, with neurological problems being the most severe. Vaccination of dogs against distemper is highly effective, and has greatly reduced the impact of this virus on the pet dog population.

Distemper cannot be transmitted to people, so the disease itself is only an animal health risk. However, there's an indirect effect of which people need to be aware. Rabies always needs to be considered in dogs and raccoons that have signs of neurological disease. If there is so much distemper in an area that people assume every sick (wild) animal they find has distemper, there is a risk that the odd (but important) case of rabies may be missed, leading to human exposure. It's easy to dismiss a neurological raccoon or unvaccinated dog as having distemper, and it usually is distemper (particular in light of the current outbreak), but the implications of missing a case of rabies can be severe since it can be transmitted to people and is almost invariably fatal.

If distemper is present in your area (or, really, even if it's not currently a problem):

  • Make sure your dog is vaccinated.
  • Keep your dog away from wild animals, especially ones that are acting strangely.
  • Keep yourself away from wild animals, especially ones that are acting strangely.
  • Don't do things that will encourage raccoons to move into your yard, like leaving out food.
  • If you see a wild animal that is acting strangely, call your local animal control agency.

Photo credit: The Star - Toronto edition 18-Feb-10