Why are rabbits in Colorado growing horns? Not a myth but a medical condition
Several residents have shared photographs which show rabbits with black ‘horn-like’ structures protruding from their heads
Rabbits with horns or tentacles on their heads have been spotted in Colorado in the US, with social media photos taken by residents creating a frenzy in the region.

Several residents have shared photographs which show rabbits with black ‘horn-like’ structures protruding from their heads.
While it may look startling, people have been looking for an explanation of this phenomenon. So is it just a myth or something else entirely?
Rabbits developing horns in Colorado is a medical condition
The rabbits developing horn-like structures on their heads in Colorado are actually suffering from a medical condition.
According to wildlife experts, the unsettling condition is caused by Shope papilloma virus, a disease that creates wart-like tumours on rabbits, often around the head, ears, and eyelids.
While the growths may look disturbing to someone who looks at them for the first time, officials stressed they do not pose a threat to humans, pets, or any other wildlife.
‘Virus only spreads between rabbits’
The experts have stressed that the virus only spreads between rabbits, typically through bites from insects such as mosquitoes and ticks. According to the University of Missouri, the condition is a DNA virus “seen most frequently in cottontail rabbits of the Midwest with outbreaks in domestic rabbits”.
The university experts explained that the virus causes benign wart-like tumours, but in some cases, these can become malignant or cancerous, causing problems for the animals.
While generally not harmful to the rabbit’s overall health, another problem that they might face apart from it being cancerous is if the growths obstruct the mouth, nose, or eyes.
The disease is relatively common in wild rabbit populations, particularly during warmer months when insect activity is high. There is no known cure for the virus, and it is only cured in domestic rabbits with surgical removal of tumours.
Colorado Parks and Wildlife is advising residents to keep their distance, while stressing that the rabbits are not dangerous.