Grotesque squirrels covered in tumors and oozing sores have been alarming residents across the US and Canada. In neighborhoods from Maine to the Midwest, homeowners say the sickly gray squirrels are turning up in backyards and around bird feeders.
Social media users on both Reddit and X have shared unsettling photos that show the rodents with raw, hairless growths spreading across their faces and bodies.
Reports of these disfigured animals date back to the summer of 2023. While the sightings initially appeared sporadic, new cases continue to surface online, including several within the last month.
Many residents have wondered whether the condition points to a wider outbreak of disease spreading through local wildlife populations.
Squirrel disease spreading outdoors
Some suspected the squirrels carried squirrel pox, a rare virus in the US that often kills red squirrels. Experts, however, point to squirrel fibromatosis as the more likely culprit. This condition comes from a leporipoxvirus that spreads when healthy squirrels come into contact with lesions or saliva from infected ones.
“It’s like when you get a large concentration of people. If someone is sick and it’s something that spreads easily, others are going to catch it,” said Shevenell Webb of the Maine Department of Inland Fisheries and Wildlife, speaking to the Bangor Daily News.
The condition leaves squirrels with wart-like growths that sometimes break open and ooze fluid. While the sores look terrifying, the virus usually runs its course without medication. Gray squirrels typically recover within four to eight weeks.
Wildlife officials warn that backyard bird feeders may be worsening the problem. Infected squirrels can leave saliva on uneaten seed, which healthy animals then eat. This allows the virus to spread quickly through local populations.
“Like a lot of people, I love watching birds,” Webb said. “Unfortunately, you can attract multiple squirrels to that feeder and risk exposure if one has the virus.”
Experts stress that the virus cannot spread to humans, dogs, or birds. They also caution homeowners against attempting to handle sick squirrels.
“I would not recommend trying to capture a squirrel that has the virus,” Webb said. “It is naturally occurring and will run its course in time.”
Condition rarely fatal
Although fibromatosis looks grotesque, the disease is rarely fatal. Most squirrels recover fully and do not experience recurring outbreaks.
Severe cases can affect internal organs, but wildlife officials stress that this outcome is uncommon.
Some social media users questioned whether it would be humane to euthanize affected squirrels. Wildlife experts say they should be left alone, since most recover naturally.
It comes as another mysterious virus in Colorado has transformed rabbits into alien-looking creatures with black tentacle-like growths sprouting from their heads.
The culprit is cottontail papilloma virus (CRPV), also known as Shope papilloma virus, which triggers tumor growths around the rabbits’ heads. Parasites such as fleas and ticks spread the virus through their bites.
Wildlife officials urge homeowners to limit close contact with backyard animals and avoid interfering with infected ones.
The growths may look alarming, but most squirrels and many rabbits heal on their own without human intervention.
