Raccoons: what are they really hiding behind that mask?

What are they hiding behind those masks?

Who could overlook the quintessentially Canadian animal that is the raccoon? Though many people often only think of these animals as mischievous trash raiders, these urban specialists have adapted well to our human-dominated cities and landscapes. Unfortunately, they don’t only bring their good looks, as many of these raccoons can harbour an internal parasite that poses a health threat to both people and other domestic animals.

Raccoon roundworm

The raccoon roundworm, more formally known as Baylisascaris procyonis, is a common parasite that infects wild raccoons and lives in their small intestines. These parasites do not usually make the raccoons sick, unless there are large numbers of them. But when they defecate, they can deposit eggs from these roundworms in their feces. Us, our family pets, as well as other wildlife such as squirrels, groundhogs, and even animals such as white-tailed deer can become infected with this parasite and suffer severe consequences. In animals other than the raccoon, the parasite tends to get confused and will migrate out of the intestine and can end up in places like the eyes or brain, which can cause severe illness and and even death.

Because of the high prevalence of this parasite and the concerns for human infection, the CWHC has been involved in a multi-year project analyzing raccoons all across Ontario in partnership with the Ministry of Natural Resources and other organizations to determine how many of these raccoons are infected and where they are from. This type of research allows us to track the trends of this parasite over time, and help educate both the public and local health departments to take measures to prevent human or pet infections.

Thankfully, human infection is very rare, and there have only been a handful of cases in Canada in the past, some of which are discussed here in an article from 2012. However, human and pet infections are easy to prevent with some basic hygiene and common sense. Remember to wash your hands after spending time outside after activities such as gardening. Watch young children closely outside to make sure they are not putting inappropriate things in their mouths, and promptly cleaning up any raccoon feces around homes and in backyards to reduce or prevent the chances of infection.

More information on the raccoon roundworm can be found here.

This is part of a series of photo essays submitted by the wildlife rotation students at the Ontario Veterinary College and the Ontario/Nunavut region of the CWHC.
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