Recently, some wild rabbits have been seen in the U.S. with "horn-like" growths spurting from their heads that are caused by a viral infection, according to experts."Rabbit papillomas aregrowths on the skin caused by the cottontail rabbit papillomavirus," Colorado Parks and Wildlife (CPW) says on its website, as some people in the state have reported the strange sightings."It looks like it was black quills or black toothpicks sticking out all around his or her mouth," Fort Collins, Colorado, resident Susan Mansfield, who saw one of the rabbits, told 9News. "I thought he would die off during the winter, but he didnt. He came back a second year, and it grew."NUCLEAR PLANT ON COASTAL WATERS SHUT DOWN OVER MASSIVE JELLYFISH SWARMCPW says the infection is typified by "black nodules on the skin, usually the head," adding, "Growths can sometimes become elongated, taking on a hornlike appearance."The department says the growths dont harm the rabbits unless they interfere with the animals ability to eat and drink.RARE TICK-BORNE VIRUS CAUSING NEUROLOGICAL SYMPTOMS DIAGNOSED IN NORTHEASTERN STATE"Most infected cottontails can survive the viral infection, after which the growths will go away," CPW says. "For this reason, CPW does not recommend euthanizing rabbitswith papillomas unless they are interfering with the rabbits ability to eat and drink."The department says the virus is specific to rabbits and cant be transmitted to other species, but it could infect domestic rabbits, "especially if rabbits are housed outdoors where they may contact wild rabbits or biting insects. In domestic rabbits, the disease is more severe than in wild rabbits and should be treated by a veterinarian."CPW also advises people to avoid touching infected rabbits, according to News9.CLICK HERE TO GET THE FOX NEWS APPThere is no known cure for the virus.