🐰 Why Do Rabbits in America Grow Horns? And How Is It Related to HPV?
In northern Colorado, a large number of wild rabbits have been found with horn-like growths on their heads and faces. While these "horns" often resemble the terrifying fungi from The Last of Us, they are usually not a serious threat to the animals' health. The culprit is the Shope papillomavirus, which is similar to the virus that causes warts in humans.
The infection is spread by mosquitoes, ticks, and fleas. The virus only affects rabbits and hares and is not contagious to humans. Over time, the rabbits' immune systems typically fight off the disease, and the horns—made of keratin, the same protein found in fur and claws—simply fall off.
Zoologists note that in rare cases, the infection can lead to skin cancer in rabbits, and the growths can become life-threatening if they interfere with eating or foraging. For example, this can happen if the growths form around the eyes or mouth.
ℹ️ The discovery of the Shope papillomavirus in 1933 laid the foundation for understanding human papillomavirus (HPV) strains. This eventually led to the development of the HPV vaccine, which reduces the risk of cervical cancer and other types of cancer in humans.
