Being over 4000 miles apart, it’s no wonder that the diversity of wildlife in Minnesota is completely different to that of the UK, but along with different animals, comes different diseases, and many different parasites.
A parasite which I have not encountered before my time here at the WRC is a type of roundworm, whose host is the raccoon. This parasitic worm is called Baylisascaris procyonis. It usually spends its life inside the gut of a raccoon, periodically shedding its eggs within the raccoon’s feces. To the raccoon, it is virtually harmless, but very widespread, infecting up to 70% of adults and 90% of juveniles. If it is harmless though – then why write a blog about it?
Since my time at the WRC, numerous other, ground-feeding animals, such as squirrels, rabbits and woodchucks have been brought in with suspected Baylisascaris infections. These animals have accidentally ingested the eggs along with their food whilst foraging. When this happens, the parasitic larvae migrate to their brain or eyes, which is not only potentially fatal, but can also cause visual impairments, substantial neurological damage and considerable lack of coordination.
I’ve also learned that Baylisascaris is a potential threat to humans. It most commonly affects children, as they are more likely to ingest contaminated soil or sand to which raccoons may have access. Unfortunately, there is no treatment which is known to completely eradicate the disease in humans, and in cases where the infection is not fatal, severe neurological damage can occur, along with blindness.
This is the direst warning we can give to people who find orphaned raccoons in their yard, and with the best intentions, want to care for and rehabilitate them. Not only is this illegal without the necessary permits from the DNR, but it is also incredibly dangerous.
On a positive note – not all of the infected animal patients admitted to the WRC suffer fatal damage from the parasite. Sometimes the worm causes only a slight visual impairment, or some minor imbalance. One of the neurological effects of the worm can also be a decrease in aggression, and lack of fear of predators. Although these particular animals would not do well in the wild, it does make them ideal for placement, given that they do not become stressed in the presence of humans.
Recently, an infected female woodchuck came in that stole the hearts of everyone at the WRC, not only was she approachable and friendly toward humans, but the sight of her munching on a carrot in her enclosure was enough to make anyone smile.
Happily, she was able to be placed at the Staten Island Zoo in New York, where she will educate a whole new generation of children to love wildlife as much as we do!