They’re lethargic, and having trouble climbing trees.

A Fairfax County Police spokesman said residents are calling Mount Vernon authorities about recent sightings of raccoons behaving oddly. But it’s no joke: One raccoon just tested positive for canine distemper, the spokesman said Friday.

Police spokesman Eddy Azcarate said one of five raccoons that were collected by animal control officers over the past three weeks had tested positive for the disease. He said the disease is highly contagious and potentially deadly for dogs.

The raccoons were found in the area of Fort Hunt Road and Namassin Road, according to a press release.

Symptoms of canine distemper include sneezing, coughing and thick mucus from the eyes and nose, the release said. Other signs include fever, lethargy, sudden vomiting and diarrhea, depression and/or loss of appetite. The release also said the virus can affect skunks, foxes and coyotes.

Azcarate said police are recommending that all dog owners verify that their pets’ vaccinations are up to date and watch for symptoms.