Colorado’s “Frankenstein Bunnies” Are No Danger To Us, Scientists Say

This week, a group of rabbits hopping around in Colorado has aroused online attention due to the warty, grotesque, tentacle-like protrusions growing out of their faces, almost like horns. These unsightly growths are caused by a virus known as the Shope, or cotton-tailed, papillomavirus.

While the internet has been terrified by viral videos of these bunnies, the virus that caused such monstrous growths is actually quite exclusive to cotton-tailed rabbits and rarely infects other species. “The virus won’t infect most household pets,” writes Hannah Ziegler for the New York Times, “but people should keep pet rabbits indoors if they see infected wild rabbits in their area…[as] the disease is more severe in domesticated rabbits and can cause cancer, according to a National Institutes of Health study.” Humans are also largely unaffected by the disease, though contact with infected rabbits is not recommended by scientists.

This specific type of papillomavirus infects rabbits mostly through biting insects like fleas and mosquitoes, making it much more common during bug-infested summers. While there is no known cure to this disease, most rabbits’ immune systems can deal with it on their own. Even while having the virus, rabbits are usually not in much danger as long as no outgrowths sprout on their eyes or mouth, limiting sight and the ability to eat, respectively.

Since the Shope papillomavirus isn’t fatal to its lagomorph hosts, carriers of the virus are more likely to be spotted by humans than other, more lethal diseases. Stories of rabbits with deer-like horns have been circulating in North America for at least a century and even longer in other places in the world. These myths include the famous Jackalope, as well as many Bavarian tales, and even some early scientific texts, where they named horned hares as a real species of rabbits. As Micaela Jemison states in a Smithsonian article, “Stories and illustrations of horned rabbits as real animals last appeared in scientific books in the late 1700s, after which the idea of a horned hare as a distinct species was mostly rejected.”