Distemper, a serious and highly contagious animal disease, has broken out among raccoons on the Eastside, and health officials are encouraging dog and ferret owners to make sure their animals are vaccinated and kept away from wildlife.

On Friday, King County health officials learned that two dead raccoons -- one from Bellevue, the other from Redmond -- tested positive for the disease. Several dead raccoons have also been picked up in Issaquah, and are assumed to have died of distemper as well, said King County spokeswoman Christine Lange.

Humans and cats aren't affected by canine distemper, but it's highly contagious among dogs, ferrets, raccoons, coyotes, skunks, weasels and harbor seals.

"Dogs are normally vaccinated against canine distemper, but the disease has become generally uncommon and some pet owners are not getting their pets vaccinated," said Sharon Hopkins, the veterinarian for Public Health -- Seattle & King County, in a press release from the King County health agency, the Washington Department of Fish and Wildlife, and PAWS. If you don't know whether your pet has been vaccinated, call your veterinarian, Hopkins said.

Distemper causes encephalitis, or inflammation of the brain, in animals. Infected animals may have runny eyes and stagger, tremble, foam at the mouth or snap, according to veterinarians. It can be transmitted by bodily fluids, including urine and feces, and is nearly always fatal, Lange said.

"While we have seen an increase in the number of raccoons this year at our wildlife hospital that appear to be infected with canine distemper, we encourage people not to panic," said PAWS' wildlife veterinarian John Huckabee. "The best way to avoid potential exposure to pet dogs and ferrets is to avoid feeding or otherwise attracting wildlife, intentionally or unintentionally."

People are encouraged to feed pets indoors, and secure garbage, compost, bird feeders and chicken food to keep wild animals out. Residents should also secure pet doors so that raccoons cannot enter indoor living spaces.

"Remove any reason for wild animals to come across your yard," Lange said. "Don't give them a chance to come up to your house or be around your property."

Just because a raccoon is moving around during the day, it may not necessarily be sick, Lange said, but an ill raccoon might foam at the mouth, snap at you or be slow to move. If you live in King County and come across a raccoon that appears to be sick, call (206) 296-PETS to receive information and suggestions about potential resources. Animal control officers will pick up dead raccoons.

The Department of Fish and Wildlife offers advice for dealing with problem wildlife on its Web site at http://wdfw.wa.gov/wlm/living/, and the PAWS Wildlife Center, (425) 787-2500 x817,offers tips for solving and preventing conflicts.

Lange said there has also been in outbreak in Los Angeles, where more than 40 dogs have come down with the disease.

Wildlife officials said diseases run in cycles through wild animal populations, and overpopulation will often cause an outbreak.