Warts in dogs are caused by a virus called a Papillomavirus. While humans can get warts too, pet owners are not in danger from contracting warts from their canine companions. Warts between dogs are extremely contagious, but normally a wart growth does not appear unless the dog is very young or the dog has a compromised immune system.
There are two types of warts which can occur in dogs. The first type occurs mainly in older dogs, and they develop as a result of a weakened immune system. The second type of wart occurs from the canine papilloma virus; these warts generally develop in younger dogs.
In cases where warts in dogs need to be removed they are removed through electrocautery, cryosurgery, and laser removal. In rare cases of severe wart infections, interferon treatment is sometimes administered.