Can dogs get warts?
Dogs warts, not dissimilar to those seen in people, are relatively common in young dogs. However, most of the bumps that we think of as "warts" on the skin of older dogs are technically not warts at all. Nevertheless, they're commonly referred to as "warts" by veterinarians and pet parents alike. Here are more details about wart-like bumps as well as true dog warts.
What Is a Wart? (& Can Dogs Get Warts?)
A true wart is a virus-induced proliferation of superficial skin cells technically referred to as a viral papilloma. As with human warts, warts grow when a virus gets into the cells of the skin and change how the skin tissue grows, resulting in an unsightly bump.
Dog warts sometimes fall into the category better known as "wart-like," which means they're not virus-related but still look every bit like a wart. These bumps are exceedingly common in older dogs. They are proliferative skin masses that can grow anywhere on the skin and are typically no larger than the size of a pea. They are usually hairless and firm, but sometimes they exude waxy debris or even bleed.

What Causes a Dog Wart?
True dog warts occur in conjunction with papillomavirus infections, they are typically found in young dogs and most commonly in the mouth or around the face or genitals. Dogs are often infected after directly or indirectly coming in contact with other dogs in their community. To distinguish these bumps from other wart-like masses, veteterinarians refer to them as viral papillomas.
The cause of most wart-like masses seen in dogs is less clear, but the vast majority are considered sebaceous gland growths. Excessive division occurs in cells of the sebaceous glands of the skin and this leads to growth in a wart-like pattern. Thankfully, these growths are almost always benign.
A variety of wart-like, sebaceous gland growths are seen in dogs. Nodular sebaceous hyperplasia is the most common. They are typically round or cauliflower-shaped and may or may not ooze or bleed. These growths are seen most often in breeds such as Cocker spaniels, Miniature poodles, Miniature schnauzers and Beagles but can occur in any dog. Other forms of sebaceous gland growths include what are technically considered tumors another word for cancer. These include the sebaceous epithelioma, sebaceous adenoma and sebaceous carcinoma. This latter category is a malignant cancer, which is rare as it only occurs in about 2% of sebaceous tumors.
Dogs of all ages can get true warts or wart-like masses, but the rule of thumb is that young dogs get viral papillomas while old dogs get wart-like masses that are classified as either nodular sebaceous hyperplasia or sebaceous tumors.
