Canine papillomavirus in dogs is caused by a group of viruses that lead to various skin and mucous membrane lesions. These viruses target the epidermis and epithelial tissues, such as those found in the mouth and nose. Resistant to many disinfectants, papillomaviruses can survive in the environment and complicate infection control.
Depending on the virus strain, the dog’s immune system, and the lesion location, several clinical presentations are possible.
Oral Papillomatosis: Common in Young Dogs
Oral papillomas are the most frequent form, especially in young dogs. These warty lesions typically appear inside the mouth but can also develop on the lips, nose, or around the eyes. Early signs include small red papules or white plaques, which later grow into cauliflower-like masses. Most resolve on their own within 4 to 8 weeks. Rarely, persistent lesions can become cancerous.
Exophytic Cutaneous Papillomas: Head and Feet Lesions
Seen in both young and senior dogs, exophytic papillomas appear as solitary or multiple masses, often on the head, eyelids, or feet. They are pink, white, or pigmented and can be either stalked or sessile. These papillomas typically regress within 6 to 12 months.
Inverted Cutaneous Papillomas: More Severe and Persistent
These firm, raised, and non-pigmented lesions have a central pore and are usually under 2 cm in size. Found on the abdomen, groin, or limbs, they affect dogs under 3 years old and don’t regress naturally, often requiring treatment.
Pigmented Plaques: Genetic Links Suspected
Mainly affecting young adult breeds like Pugs and Miniature Schnauzers, these dark skin patches appear on the neck, limbs, and belly. They are suspected to have a genetic origin and are more common in immunosuppressed dogs. Though generally benign, they can sometimes evolve into skin cancer.
Pigmented Papules: Small Lesions on Ears and Abdomen
These small (<2 mm), black papules are commonly found on the concave side of the ears and on the abdomen. They often resolve after corticosteroid therapy is discontinued.
When Is Treatment Necessary?
Most canine papillomas are self-limiting and require no treatment. However, if lesions persist, become painful, or risk becoming malignant, medical intervention is warranted. Options include:
- Surgical removal
- Cryotherapy
- Laser ablation
Antiviral and Medical Treatments
Medications such as azithromycin (an antibiotic with antiviral properties) can treat oral and cutaneous papillomatosis. Imiquimod, an immune-response modulator, is effective when applied topically. Although interferon has shown promise in humans and dogs, no controlled studies confirm its efficacy or safety in canine cases.
When to See Your Veterinarian
If your dog develops unusual skin lesions, especially those that persist or change in appearance, consult your veterinarian promptly. Early diagnosis ensures appropriate treatment and prevents complications from canine papillomavirus.
