Just when people were still wrapping their heads around stories of Colorado’s so-called ‘Frankenstein rabbits’ and even ‘Zombie squirrels,’ another unsettling sight has been reported—this time in Pennsylvania and Wisconsin, where deer are showing signs of these strange lumps.
Photos and videos quickly made their way across social media, showing deer wandering around with large warty growths covering parts of their bodies.
Not long after, another person uploaded an image of a deer with swollen lumps on its chest and face, asking bluntly, “what’s wrong with this deer?”
So, what exactly is going on with these animals?
What is deer fibroma?
According to the Maine Department of Inland Fisheries and Wildlife, these unusual lumps are actually the result of a condition called deer fibroma. It develops from ‘a species-specific papillomavirus’ and is similar to the cottontail rabbit papilloma virus (CRPV) that affects rabbits in the wild.
They further note that while most infected deer usually only have a small number of these fibromas, it isn’t rare to see cases where the growths are much larger and spread widely across the skin.
Is deer fibroma contagious to humans?
Thankfully, just like CRPV in rabbits, deer fibroma cannot spread to humans or other species—it remains confined only to deer.
Wildlife veterinarian Dr. Kristin Mansfield explained to FOX13 that deer often transmit the virus to each other through shared spaces like feeding areas, resting spots, or rubbing posts on trees, which bucks commonly use during mating season.
Still, deer can carry ticks that spread other illnesses like Lyme disease, meaning they can indirectly pose health risks when living near people.
Can deer fibroma be treated?
Currently, there is no direct medical treatment available for deer fibroma. In some rare cases involving captive animals, the growths may be surgically removed.
For wild deer, however, the general advice is to leave them alone, since the condition usually resolves naturally. Sadly, if the fibromas become so severe that the deer can no longer eat, see, or move properly, then euthanasia may be considered as a last resort.
What could be driving the rise in these ‘mutant animal’ cases?
One of the possible explanations is climate change. Warmer temperatures have allowed ticks and mosquitoes to thrive in areas where they were not as common before, creating opportunities for diseases to spread more widely.
Highlighting the issue, Dr. Omer Awan from the University of Maryland School of Medicine told The Daily Mail: “These temperature changes are resulting in diseases that were never endemic in certain areas to become endemic.”
“If you take a look at Lyme disease, for example, we’re starting to see it in areas that we never saw it before… places like southern Canada, northern states on the East Coast, like Maine.”
