DENVER — A group of rabbits in Colorado has been spotted with unusual hornlike growths, leading to a flurry of attention and nicknames like "Frankenstein bunnies" and "zombie rabbits." However, experts say there is no cause for alarm. The rabbits, seen recently in Fort Collins, are infected with the Shope papillomavirus, a virus that is mostly harmless to them.

The Shope papillomavirus causes wart-like growths that can protrude from the rabbits' faces, resembling horns. This condition is not new; it has been documented for nearly a century and has even influenced folklore, such as the jackalope myth, which describes a rabbit with antlers.

The virus was first identified in the 1930s by Dr. Richard E. Shope, a professor at The Rockefeller University. It has played a significant role in scientific research, particularly in understanding the relationship between viruses and cancer, including the human papillomavirus linked to cervical cancer.

Residents of Fort Collins, located about 65 miles north of Denver, began sharing photos of the rabbits, which led to increased public interest. Kara Van Hoose, a spokesperson for Colorado Parks and Wildlife, confirmed that the agency has received numerous calls regarding the sightings. She noted that it is not uncommon to see infected rabbits, especially during the summer months when fleas and ticks, which can transmit the virus, are more active.

Van Hoose explained that while the virus can spread among rabbits, it does not affect other species, including humans and pets. The growths, which can appear wart-like, may take on a horn-like appearance if they grow longer. Generally, these growths do not harm the rabbits unless they develop on sensitive areas like the eyes or mouth, potentially interfering with eating.

Fortunately, rabbits have robust immune systems that can combat the virus. Once their immune systems successfully fight off the infection, the growths typically disappear.