Wildlife officials in northern Colorado have spotted rabbits with unusual horn-like growths on their faces. The bunnies are infected with Shope papillomavirus, a viral infection that affects only rabbits and hares. According to Kara Van Hoose, spokesperson for Colorado Parks & Wildlife, the virus is typically harmless to most rabbits and can be cleared from their system on its own.
The growths, made of keratin found in hair and nails, will eventually fall off once the virus is gone. However, in rare cases, the infection can lead to squamous cell cancer or cause problems if the growths interfere with the rabbit’s vision or eating abilities. Thankfully, wildlife officials say the horned rabbits are not a danger to other animals or humans, and most infected individuals will recover without issue.
Source: https://www.scientificamerican.com/article/why-are-rabbits-sprouting-tentacles