A researcher with the University of Saskatchewan is trying to figure out why a parasite commonly found in felines is thriving in Arctic foxes in Canada's North.

Émilie Bouchard has been studying one of the world's most successful parasites commonly found in warm-blooded animals, including humans, called toxoplasma gondii. It's estimated up to a third of the world's population is infected.

"Its main carrier is the feline family — so wild and domestic cats. And we know there's not a lot of cats above the Arctic Circle," she said.

"We were wondering why it was that high in a place where no cats are present," Bouchard said, adding previous studies estimate around 60 per cent of Arctic foxes have been exposed to the parasite.

Arctic foxes 3

Bouchard says if a fox becomes exposed to the parasite while pregnant, it can have harmful effects on the fetus and on the pups. (submitted by Émilie Bouchard)

One way Arctic foxes could be exposed to the parasite is by eating animals who have previously been exposed. Arctic foxes prey on caribou and geese, migrating animals who may come across cat feces containing the eggs of the parasite down south, and then bring it back north.

Bouchard said she's found evidence that a pregnant mother can also transmit the parasite to her pups via the placenta, known as vertical transmission. 

"We caught a mom last year. She has anti-bodies against the parasite which means she has been exposed and she might be infected. And then we trapped a lot of her pups and all of the litter was actually positive for antibodies," she said.

If a pregnant mammal is infected with the parasite, Bouchard said it can have harmful effects on the fetus, potentially causing spontaneous abortion.

If the parasite can be passed to the pups through the mother and onto another generation of foxes, Bouchard said it could explain why the bug is showing up in so many of them. 

"It gives us information about why this parasite is so successful in the Arctic."