Weanlings and yearlings commonly suffer from unsightly skin diseases. Caused by a virus, warts tend to disappear after the affected animal mounts immunity.

Andi Lear, veterinarian in the Department of Animal and Food Sciences at the University of Tennessee, says warts usually don’t hinder production, but sometimes they appear in locations that might cause problems.

“We see warts most commonly in winter and spring, and they are contagious,” Lear says. “They affect young animals more often than adults, probably because young animals may have less immunity — unless older animals have suppressed immunity for some reason.”

Warts may spread through a group of young animals in winter because they are grouped for feeding or huddled together for warmth, explains Lear. A papillomavirus specific for cattle causes growths on the skin. There are other papillomaviruses that affect horses and some that affect goats, sheep, etc. They don’t generally spread between species, so humans are not likely to get warts from handling cattle.

There are several types of bovine papillomaviruses, and some tend to affect certain areas of the body.

“The viruses can live in the environment and may be picked up when the animal rubs its head on something.” — Andi Lear

“Types 1, 2 and 3 generally cause warts around the head and neck. They appear most commonly in these areas because cattle are generally rubbing on things and on each other. The viruses can live in the environment and may be picked up when the animal rubs its head on something,” Lear explains. Cattle often scratch an itch around an ear or eye with a hind foot, and could pick it up that way or by fighting and pushing heads against one another — picking up the virus from an animal that has warts.

Type 1 can also cause warts that appear on the penis of young bulls. These warts hinder production because they can interfere with breeding.

“We see these when we do breeding soundness exams in yearling bulls,” Lear says. “Penile warts may have a pedunculated (on a stalk) or cauliflower-like mass on the penis or tip of the penis.”

These can be removed, though sometimes it can be difficult, depending on the size and amount of hemorrhage that might result. Some of these warts readily fall apart or might be like a scab that can be popped off. They can also be surgically removed, she says, noting it is important to recheck the bull later to make sure the warts are gone. While they usually heal fine, if they bleed severely, it’s important to prevent adhesions of the penis in the prepuce. If that happens, the animal can’t extend the penis for breeding.