Raccoons across London are dying because of an outbreak of distemper, a fatal disease that can affect unvaccinated dogs and cats that wildlife experts say has become increasingly common with climate change.

As many as 48 raccoons have been reported dead and had to be removed from city roads, sidewalks playgrounds and parks over the last two months, double the number reported at the same time last year. Many more have been reported sick or acting strangely.

"Right now it's peaking for sure," said Kent Lattanzio, the director of operations for the London Animal Care Centre.

The city-run agency in charge of animal welfare has been getting anywhere from eight to 15 reports a day of raccoons exhibiting peculiar behaviour.

"It might appear, for a lack of a better term, a little spaced out. It might be reaching just into the air and it might be wobbling, falling over," he said.

What is distemper?

Scott Weese urges people to stay away from wild animals, including raccoons. (Wilfredo Lee/The Associated Press)

Distemper is a fatal virus similar to rabies. While it poses no threat to humans, it does affect a wide array of animals, including raccoons, skunks, coyotes, foxes, cats and dogs.

Raccoons with distemper often move slowly and may appear to limp, stumble or wander aimlessly. They often have a mucus discharge that appears around their eyes and nose, can suffer tremors and lose their fear of humans.

"We've had several reports of raccoons scratching at back doors like they want to come in sort of thing," said Brian Salt, the founder of Mount Brydges-based animal rehabilitation centre Salthaven.

He said he's been getting half a dozen reports a day of raccoons acting in a peculiar way this winter, including chewing fits.

"For whatever reason the virus makes the pads of their feet very stiff and they don't like that and they start chewing so you get this self-mutilation thing going on to the point where they leave blood trails when they walk," he said.

"We've even had reports where they chew their own tails off."

Make sure your pets are up to date on their shots

A young raccoon (not in this picture) was found in an apparently electrified cage in Vancouver, the B.C. SPCA said. (Katy Thompson)

Salt said raccoons can carry both canine and feline distemper, so its important that pet owners make sure that their pets are vaccinated against the illness.

"That virus can hang out in the environment for literally months in the right conditions," he said. "The raccoon has come and gone but the virus is still in the backyard and you let your dog out. Boom! You got a problem."

"Any responsible pet owner is going to make sure those shots are up to date."

Salt said distemper has always been around, but climate change is making winters warmer and the disease is becoming increasingly frequent.

"It seems to be coinciding strangely enough with the warming of our winters. When the winters are cold, we don't have near the number of animals with distemper as we see now."

"The warmer our winters get, the less likely that disease is going to die in the den," he said.

Brian Stevens, a wildlife pathologist who works at the Canadian Wildlife Cooperative at the University of Guelph said the illness used to come in waves, but now it's become present on a steady basis across the province.

"It actually seems to be a pretty consistent thing we're seeing," he said. "So far this season, I've seen four raccoons and all four were distemper positive."

"I'd say out of all the raccoons I do, 80 to 90 per cent die from distemper and we're really not sure why that is."

Stevens said while more study is needed, the current theory is that like humans, disease spreads quickly among raccoons living in dense urban environments.

"We think it has more to do with cities than anything else," he said. "They're doing quite well in the cities. Their population has skyrocketed since they've learned to live with humans."

"We suspect it's the urban raccoons coming in contact with each other and spreading it around," he said. "I don't know if it's worse this year than other years, but if people in the field are seeing it then it probably is."

What to do if you see a raccoon acting strangely

Anyone who suspects a raccoon of having distemper is urged not to feed it or approach it.

The animals can become aggressive if cornered, even if the illness is making them appear friendly.

Instead, neighbours are asked to call London Animal Care Centre at 519-685-1330 and a by-law officer will be dispatched to investigate.

Dead animals on public property should be reported to the city works department at 519-661-4965.