Pet owners often worry if they can contract warts from their dogs. These small, benign growths, known as canine warts or papillomas, are caused by a specific viral infection. The risk of transmission to humans is virtually nonexistent because the virus is highly adapted to its host species. Canine warts are generally harmless to the pet and pose no threat to the human members of the household.
The Science of Species Specificity
Canine warts cannot spread to humans due to the biological principle of species specificity, which governs most viral infections. The growths seen on dogs are caused by Canine Papillomavirus (CPV), a virus distinct from the Human Papillomavirus (HPV) that causes warts in people. Papillomaviruses are highly specialized, meaning they can only successfully infect the cells of their specific host species.
A virus must attach to specific receptor proteins on the host cell’s surface to gain entry and replicate its genetic material. The CPV is designed to recognize and bind only to the receptors found on dog cells, making human cells functionally incompatible. This biological lock-and-key mechanism ensures that a dog’s viral warts are transmissible only between dogs.
Identifying Canine Papilloma
Canine papillomas typically present with a distinctive appearance. They are benign tumors that often have a rough, textured surface, frequently described as looking like a small head of cauliflower. These growths usually range from a few millimeters up to a centimeter in diameter and can be flesh-colored, pink, or slightly darker than the surrounding skin.
In young dogs, the warts are most commonly found in or around the mouth, such as on the lips, gums, and tongue. In older dogs, solitary warts may appear on the skin, including on the eyelids, feet, or abdomen. Many viral papillomas will spontaneously regress as the dog’s immune system matures and develops a defense against the virus.
When to Consult a Veterinarian
Although canine warts are benign and often resolve without intervention, specific circumstances warrant a professional veterinary check. A visit is recommended if the wart is located in an area that interferes with the dog’s normal functions, such as eating, breathing, or walking. Warts in the mouth, on the paw pads, or near the eye may become irritated or painful due to friction.
Owners should seek veterinary advice if a wart begins to bleed, changes rapidly in size or color, or shows signs of infection like oozing discharge. In older dogs, any new skin growth should be examined, as some tumors can resemble papillomas but may require different treatment. If a wart persists for longer than three months without showing signs of regression, a veterinarian may choose to perform a biopsy to confirm the diagnosis.