Foxes are becoming a relatively common sight in Charlottetown. (Kevin Yarr/CBC)

An parasitologist at Charlottetown's Atlantic Veterinary College is inspecting fox carcasses to keep tabs on diseases that could spread to domestic pets.

Gary Conboy estimates he will check 120 fox carcasses this year. This is the third year of increased surveillance for the program. His most common finding will be lungworm, which he expects as many as 85 per cent of them will have.

"The two places where it's most common would be P.E.I. and Newfoundland," Conboy told CBC News Tuesday.

Veterinary epidemiologists believe lungworm is common in the two provinces because both have large populations of red foxes that eat infested slugs.

Lungworm can infect domestic dogs too. That's a problem in both rural and urban areas, where foxes have become a relatively common sight in recent years. Kim MacDonald of the Montague Vet Clinic said many of the dogs she sees with coughs are infected.

"Owners will phone us and they'll say it sounds like there's something caught in my dog's throat," said MacDonald.

"It's a very distinct sound that they make."

Fortunately lungworm can be treated with an inexpensive medication. The cough disappears within a couple of days.

Watching for French heartworm

Conboy is also watching for another parasite that would not be so easily treated.

The French heartworm, a European pest, is already in foxes and dogs in Newfoundland. They have been no cases yet on P.E.I., but Conboy believes there's a good chance it will arrive eventually. The parasite thrives in the same environmental conditions as lungworm.

Heartworm can be deadly for dogs if it's not treated.

"Some dogs will develop signs of central nervous system disease, actually may start to seizure," he said.

If heartworm does come to P.E.I., Conboy hopes to be able to give vets an early warning, so they can prescribe a preventative medication for Island pets.