What you need to know about the virus that is turning animals into 'zombies'

Cases of "Frankenstein rabbits" and "zombie squirrels" are making headlines even before Halloween . Here's what you need to know about the virus that turns animals into "zombies."

Reports of rabbits and squirrels with bizarre warts, some filled with pus, have been popping up across North America. Rabbits found in Colorado appear to have multiple horn-like growths on their faces, giving them the appearance of creatures from nightmares. Squirrels have also been spotted in Maine, as well as parts of eastern Canada, with pus-filled warts and unusual hair loss.

While these poor animals may not look pretty, officials say humans have nothing to worry about. They are infected with fairly common viruses that do not affect humans, except perhaps emotionally. No one wants to see a cute wild animal sick.

Causes of rabbit horns

When observing wild animals, allowing them to roam freely is not only respectful, but also safe. In fact, some animals carry diseases that can be passed from animals to humans. Fortunately, in the recent case of rabbits in Colorado, the disease they were carrying is not contagious to humans.

Colorado rabbits are infected with a virus called Shope papilloma virus. Rabbits, primarily cottontails, are infected by arthropods such as ticks. The virus causes horn-like structures to grow from the rabbit's face, head, or neck. Sometimes, the horns interfere with the rabbit's ability to eat, and the rabbit can die of starvation.

Horns are made primarily of keratin, the same material that makes up hair and fingernails. Richard E. Shope, the researcher who first discovered the disease, called the tumors keratinocytes, or cancerous tumors.

It is possible that a rabbit infected with the Shope papilloma virus inspired the legend of the horned rabbit, a mythical creature with deer antlers often seen in many tourist shops in the American West.

It's not just rabbits, some people have found squirrels in the northeastern United States with unusual, pus-filled lesions and patches of hair loss. The condition is called squirrel pox or squirrel fibroma. Squirrels can contract the virus through mosquito and flea bites, or through close contact with infected squirrels. Lesions often develop around the area of ​​an insect bite.

Like rabbits, the disease is not transmitted from animals to humans and most squirrels will recover unless the disease interferes with their ability to eat or breathe.

What should I do if I see an animal infected with this virus?

According to experts, it is best to avoid close contact with them. Instead, report to the authorities for appropriate treatment. Viruses are always changing and no one can predict anything. Therefore, it is always good to be cautious when exposed to pathogens.

Samuel Daniel

Update 23 August 2025