Effects of Warts – From the Dog’s Point of View
Canine warts, also known as fibropapillomas or papillomas, are usually painless and benign. They tend to develop in the mouth (oral cavity papillomas) and on the superficial skin layers (cutaneous papillomas). Warts in the oral cavity can cause discomfort, drooling and bad breath. Depending on where they are located, warts in the mouth can interfere with a dog’s ability to grab, chew and swallow normally. Warts on the skin often show up on the lower legs and feet, especially on the footpads and between the toes. Warts in these locations can become annoying to the animal and cause it to lick and chew at the affected areas. This, in turn, may lead to bleeding, pain and/or lameness and may predispose the dog to developing secondary bacterial skin infections.
Symptoms of Warts – What the Owner Sees
Warts can develop anywhere on a dog’s body and frequently show up in the mouth, on the face, around the eyes and on the feet and lower limbs. Owners of dogs with warts may notice one or more of the following signs:
- Raised lumps or bumps on the skin, especially on the feet and face, in the mouth and around the eyes.
- May be rough and pedunculated, with multiple frond-like attachments to the skin or mucosa, resembling tiny cauliflowers
- May be smooth
- May be isolated/solitary
- May occur in clusters
- May start and stay small
- May increase in size and number
- May or may not bleed or be irritated by self-trauma from scratching or chewing
- Older dogs tend to develop isolated warts, commonly on the feet, around the toes and footpads and on the under-belly
- Younger dogs typically develop warts in clusters, often inside the mouth, around the eyes and elsewhere on the face or genitalia. Puppies are especially prone to developing warts, because they have naïve immune systems and enjoy licking and romping rambunctiously with other canine playmates.
Warts are usually painless and generally do not require treatment for medical reasons. Some owners want to remove their dog’s warts for cosmetic reasons, or if they cause the dog discernable discomfort such as lameness when they are between the toes or affecting the footpads, or when they interfere with vision or eating. While most warts are harmless, they can bleed and become ulcerated, infected and painful if scratched or chewed. Occasionally, warts can transition to malignant squamous cell carcinoma, although this is rare. Most warts in dogs regress spontaneously within one year.
Dogs at Increased Risk
Young dogs and dogs with compromised immune systems, especially those with skin abrasions or damaged mucous membranes, are predisposed to developing warts. Warts on the skin (cutaneous papillomas) are more common in intact males, which may be related to their tendency to be aggressive and to engage in physical confrontations with other intact male dogs. Cocker Spaniels, Pugs, Miniature Schnauzers and Kerry Blue Terriers seem to develop warts more frequently than do other breeds.