Getting Warts in Dogs

If you’ve noticed round, cauliflower-like growths on your dog’s skin and mucous membranes, then he may have acquired a DNA virus. Warts, also called viral papillomas, are the result of a papillomavirus infection. These are highly contagious viruses specific to dogs that can be spread through contact with the virus itself. The growths that form are most often found as single or multiple growths on the lips, tongue, gums, muzzle, eyelids and eyes, and between the toes, but they have also been seen on the abdomen, legs and groin. When they affect the oral cavity, then the virus is called canine papillomavirus 1.

While the warts themselves are harmless, they may begin to interfere with your dog’s normal functions, such as chewing or swallowing, or become a source of discomfort. If your dog bites them, they can bleed and become infected. Besides the presence of the warts, other signs of an oral papilloma infection include a foul mouth odor, bloody discharge from the mouth, and breathing or swallowing problems. On rare occasions, the growths can develop into cancer. 

Ways your dog can become infected with viral papillomas include:

• Direct contact
• Indirect contact
• Vaccination
• Compromised immune system

Warts are abnormal cells that are caused to grow by a papillomavirus. Once your dog acquires one of these viruses, it can take up to 1 to 2 months before you see any warts appear. Your dog is still infectious during this time and can spread the virus to other dogs. The virus is spread through:

Direct Contact 

Direct contact with an infected dog is the main path of transmission. This contact between dogs can occur anywhere that dogs interact, such as in a kennel or dog park, and can be as simple as licking each other. The virus can enter your dog’s body through the mucosal surfaces of the mouth, or through a break in the skin from any cuts or scrapes. An infected insect could also spread the virus through a bite.

Indirect Contact

The virus can survive from 6 hours to 2 months, and can be transferred to a dog through indirect contact with a contaminated surface or object. Items then can transfer the virus to include food and water dishes, toys, grooming tools, and bedding.

Use of Vaccines

The virus can also be acquired through the use of vaccines. When warts appear due to a vaccine, it can mean that your dog has been over vaccinated, or that he has had a negative reaction.

Compromised Immune System

Since the papillomaviruses are so contagious, it has been assumed that most dogs have been exposed to one at some point in their lives. While many dogs may carry the virus without presenting any warts, those with compromised immune systems are the most at risk for these growths. This can include younger dogs whose immune systems are still immature, older dogs whose immune systems have become weaker with age, and those dogs whose immune systems have been suppressed, such as through the use of immune suppressing drugs like glucocorticoids.

If you have noticed growths on your dog, you should take him to the vet to be sure they are benign. Though warts are only contagious to other dogs, they can look like other growths that may be indications of a more serious condition than a papillomavirus.

Your veterinarian will ask many questions about recent behaviors, any symptoms you may have noticed, and the history of the growths. Then, after a physical exam, your vet may perform an oral exam, especially if the warts are located in or around the mouth. In many cases, the appearance of viral papillomas is enough for your veterinarian to make a diagnosis. To be definite, a sample can be taken and analyzed, such as with a fine needle aspirate, scraping, or biopsy. 

If your dog has warts resulting from a papillomavirus, then he should be quarantined from other dogs until the all the growths have resolved. Often, the warts will spontaneously regress within 1 to 6 months, and may not need any other treatment. In some cases, your veterinarian may crush some of the warts to release the virus into the bloodstream and speed up the response of the immune system. Since the warts are benign, they are usually only removed if they are compromising your dog’s quality of life. A wart in between the toes can cause discomfort and trouble walking, while those in the mouth can hinder eating and drinking. They can also become infected and bleed.

Treatment can come in the form of medications, specifically antibiotics to protect against infections and swelling, and topical drugs to boost the immune response, such as imiquimod. A vaccine can be made from the warts that can be used in your dog as well. Removal is recommended in severe cases, and can include surgical removal and freezing techniques. In rare instances, the viral papillomas can progress into cancerous growths.

Once your dog has had and recovered from the virus outbreak, he will carry a stronger immunity for this virus and should not be re-infected.

While it may be difficult to prevent your dog from coming into contact with a papillomavirus, you can keep his immune system strong. Factors such as providing a safe and stress free environment, clean water and air, and an appropriate diet can improve your dog’s overall health. Reducing or eliminating vaccinations can greatly reduce the potential for developing an outbreak from the papillomavirus.

Treatment for warts resulting from a papillomavirus can range up to $2000, and will depend on the severity of your dog’s particular case. On average, treatment is around $850.