Many older animals develop benign skin tumors, which veterinarians can easily remove. (pawprintsthemagazine.com)
Some Syrian hamsters develop benign skin tumors called trichoepitheliomas when infected by a virus known as hamster polyomavirus (HaPV). (smallanimalchanel.com)
Warts in dogs are a benign skin tumors caused by virus (papilloma virus). (2ndchance.info)