Viral Papilloma in Dogs

Viral papillomas, or oral warts, are small, benign skin tumors typically found on the lips, mouths and muzzles of canines. Though some papillomas may have a smooth appearance, most often you will notice a distinct cauliflower or 'sea anemone' type of appearance to the wart. You may observe a single papilloma, or more likely, the virus will lead to clusters of several. While most viral papillomas are found in the mouth region, appearing on the lips, tongue, roof of the mouth, or inside the cheeks, they may occasionally grow between toes or on the eyelid. Unless the sores, become infected, they will not cause the canine discomfort. However, if the sores become infected by bacteria in the mouth, the dog will likely feel pain due to swelling. In this case, antibiotics may be indicated.

Papillomas are bunches of abnormal cells caused by Canine Papillomavirus Type 1, a contagious DNA virus.  The virus typically affects three groups of dogs: young dogs and puppies, typically less than two years of age; dogs with immune-disorders or an acute immune suppression and older dogs who accumulate warts as they age. In healthy dogs, papillomas will typically resolve themselves within 2-3 months. The good news is that once the dogs has had the virus, they will develop an immunity and likely not experience the condition again.

One of the most common questions about viral papillomas is whether an infected dog poses a risk to adults, children, or other animals. It is important to note that this virus is not transferrable to humans or other species, and can only be passed from canine to canine. The infection is present within the lesions, and thus can be passed mouth to mouth between dogs, both in and outside the household. Shared bowls and toys are usually culprits, but also typical play behavior. Viral papillomas have an incubation period of 1-2 months. If your dog has oral papillomas, he or she may have been infected some time ago. 

Finally, as with all canine health conditions, there is no substitution for a professional diagnosis. Any lump or growth appearing on a canine’s skin or mucous membrane may be indicative of another condition. If concerned, make an appointment for a check-up with your dog’s veterinarian.

Viral papillomas are small, contagious cauliflower-shaped tumors typically found in and around the mouth. They are benign, and usually resolve without treatment.

• Presence of the papillomas
• Bad breath
• Swelling in/around mouth
• Change in eating due to discomfort

The canine papillomavirus type I develops due to:

• Compromised immune system
• Long term corticosteroid treatment
• Genetic immune weakness
• Specific age (puppies and young dogs under 2 & elderly dogs)

It is contagious between dogs only.  It is often transmitted by mouth through play and through shared bowls and toys.

Diagnosis of viral papillomas is usually done by sight. The clusters of cauliflower type sores are highly recognizable due to their distinct appearance. The papillomas are usually found in and around the mouth, so should be observable in those locations. In some instances, they may bleed and cause swelling. Behavioral changes may be noticed if the sores are painful enough to inhibit eating. 

Your dog will likely be asymptomatic unless the sores become infected by bacteria in the mouth. If that occurs, the dog will need antibiotic treatment.

The vet may advise a growth is biopsied to confirm the diagnosis.

Treatment for this condition is usually conducted in an outpatient setting. However, if the condition becomes severe and is not resolving on its own, surgery may be warranted.

Outpatient treatment

It’s important to watch the sores and see if they begin to bleed, if they increase greatly in size, or appear to cause your dog discomfort. As the immune system improves, a response will mount and likely resolve the infection.  Most papillomas will resolve themselves, and disappear within 3 months. If a healthy immune response occurs, your dog will likely not have the virus again.

Inpatient Treatment

Some dogs, especially if the sores are particularly large, may benefit from surgery. The veterinarian will remove the sores, and may culture for infection and analyse them to ensure there is no malignancy. Medication, if warranted, may be given for pain and swelling caused by a bacterial infection.

Interferon-alpha treatments are another option, but are expensive. These treatments help to stimulate an immune response to your the dog of the papillomas. Treatments occur two to three times a week.

In healthy dogs, viral papilloma virus results in small, benign mouth growths. The lesions will usually recede within 2-3 months, and most dogs will develop an immunity that will protect them from future outbreaks. If your dog has papillomas, it is important to limit contact with other dogs.  Since the virus is contagious between canines, shared bowls and toys, and mouth to mouth play must be avoided.