The Cat Parasite That Causes Toxoplasmosis Is Turning Up in Beluga Whales

The parasite Toxoplasma gondii is famous for effect on rodents. Cats are natural hosts to the parasite, and their feces can carry millions of the parasite's eggs. When T. gondii infects rats, they seem to lose their fear of cats, approaching their natural predator with curiosity rather than bolting the other way. When infects humans, toxoplasmosis can cause blindness or congenital birth defects. And now scientists have found that the parasite infects beluga whales, too.

According to work presented this week at the American Association for the Advancement of Science conference, the parasite has been found in more than 10 percent of beluga whales living off the Canadian Coast, in the Beaufort Sea. Local Inuits depend on the whales for meat, and the concern is that they might acquire an infection, either from preparing the meat or eating it undercooked. "The only way to kill [the parasites] is to freeze them, dessicate them or boil them,” lead researcher Michael Grigg told the Independent. "If there is infection in whales and the meat is not appropriately cooked then there is a risk of infection."

Although the beluga whales appear to be unfazed by the infection, researchers are puzzling over how they acquired the parasite to begin with. It could be that more and more local people own cats, whose feces get washed into the water from the powdery Arctic soil. Or it could have something to do with climate change. As temperatures warm, perhaps the parasite is altering its ecological niche. While other marine animals have been shown to carry the infection before, this is the first time it has turned up in the Arctic. 

Rachel Nuwer | | READ MORE

Rachel Nuwer is a freelance science writer based in Brooklyn.