Squirrels displaying strange, wart-like growths have been spotted across multiple U.S. states this summer, but experts clarify that this unsettling phenomenon is linked to a common viral disease that usually resolves on its own.
Reports from residents in states such as Florida, Michigan, and North Carolina detail squirrels with visible tumors on their bodies, which prompted some to call them “zombie squirrels.” However, these animals aren’t returning from the grave.
The growths appear to be associated with squirrel fibromatosis, which arises from a virus called Lepripoxvirus.
Generally, these tumors don’t seem to harm the squirrels or affect their survival. Nonetheless, there are rare cases where they could spread to vital organs, leading to weakness and lethargy, according to the Indiana Department of Natural Resources. This infection tends to spike during spring and summer, resulting in numerous social media chatter about the so-called “zombie squirrels” each year.
One Ohio resident shared on Facebook, “I found this poor squirrel in my backyard; it really scared me because it looked deformed.”
Another Facebook post featured a photo of an Eastern Gray Squirrel with “patchy fur and reddish bumps” rummaging through a backyard in Tarpon Springs, Florida. The user noted, “Due to their alarming appearance, those infected are often called ‘Zombie Squirrels.’ Thankfully, the infection usually clears up on its own, and squirrels often recover within four to eight weeks.”
Experts want to reassure the public that this virus isn’t a threat to humans or pets, such as cats and dogs. However, it’s advisable for homeowners to avoid attempts to catch these squirrels.
Shevenell Webb, a wildlife biologist with the Maine Department of Inland Fisheries and Wildlife, advised against capturing infected squirrels, stating, “It is naturally occurring and will run its course in time.”
Furthermore, because the disease spreads easily among squirrels in close proximity, Webb suggested removing bird feeders from yards, as they often attract squirrels seeking a quick meal.
“It’s like when you gather a large group of people,” Webb explained. “If one person is ill with something contagious, others will likely catch it too.”
