Wild rabbits in northern Colorado have been seen with horn-like lesions due to a viral infection.
People in Fort Collins, Colorado recently reported seeing what seem to be horned rabbits in recent weeks, resulting in these animals getting the nicknames “Frankenstein bunnies,” “zombie rabbits,” and “demon rabbits.”
However, according to American Veterinary Medical Association (AVMA), these ‘demon rabbits’ actually have Shope papillomavirus (SPV), a well-known viral infection which was first described almost a century ago.1 The virus is an endemic in cottontail rabbits and is transmitted primarily by fleas, mosquitoes, and ticks. It tends to appear in rabbits more often during warmer months when insect activity peaks.1
SPV causes wart-like tumors that could keratinize into dark, hard, horn-like projections that grow on the rabbit’s head, ears, and eyelids, which can sometimes impair their vision or feeding. For most wild rabbits, their immune system resolves the infection and the growths regress eventually. This viral infection is rarely diagnosed in domestic rabbits, but it is serious when it is because the papillomas are more likely to become malignant. For domestic rabbits, if left untreated, it can progress to malignant cancer…