Wart Virus in Dogs

Canine warts are fairly common in young socialized dogs and in multi-dog families. Similar to warts in humans, they are caused by a viral infection. They are highly contagious to other dogs, but the virus cannot be transmitted to humans or other pets. While not normally a risk to your dogs overall health, they can lead to other complications and discomfort. All dogs showing symptoms of canine warts should be evaluated by a veterinarian and quarantined from other susceptible dogs until the virus has run its course.

• Warts are most commonly seen in the mouth, nose or eyes, but skin warts can show up around the footpads, legs or groin area.
• They start as a rough patch of pink-to-white skin, and as they develop they may become darker and lumpy, resembling cauliflower.
• Your dog may only have one wart, or they may occur as an eruption of multiple warts.

Types

• The most common canine wart, Canine Papilloma Virus (CPV), is benign and cannot be transmitted to humans or other non-canine animals. This is the type seen most often in the mucous membranes of younger dogs.
• Skin warts occur more often on the abdomen of older dogs. They are slower-growing than CPV and while most often benign can, in rare cases, develop into cancer.

Canine warts are caused by a viral infection only communicable with other dogs.

The virus is transmitted via direct dog-to-dog contact or sharing common items such as food and water bowls, toys, bedding, or grooming tools.

Since the virus has an incubation period of up to 2 months, once you see physical signs of infection, other dogs in your family or social group have already been exposed for some time.

You should isolate your dog and seek veterinary advice as soon as you suspect a canine wart infection. To assure a correct diagnosis, the veterinarian will do a thorough physical examination, and get a recent health and activity history. They will do an oral exam to be sure the warts are not impeding your dog’s ability to breathe or eat. If the diagnosis is uncertain, your veterinarian may want to take a fine needle aspirate or biopsy of the wart(s) to examine under a microscope.

If there is clear evidence that the papillomatosis has visibly changed the underlying skin or cellular structure, the veterinarian may request the help of a specialist. Consulting a pathologist will help the doctor determine if dangerous viral antibodies are present within the lesions. In this event, the veterinarian will avoid popping warts, which they may choose to do to release the virus into the blood stream to expedite the body's natural removal process.

If the warts are not affecting your dogs’ ability to eat, breathe or see, the most common treatment is no treatment at all. This is referred to as “benign neglect”, or just letting the virus run its course. Over time, the dogs’ immune system will strengthen and kill the virus on its own, and the warts will simply fall off. In some cases the vet will choose to squeeze the warts themselves, releasing the virus into the blood stream in an effort to speed up the immune response. It can take anywhere from 1 to 6 months for a full recovery, and during this time, the dog will have to be quarantined from any other susceptible dogs. The good news is, once a dog has healed from a CPV infection, they will carry immunity from the disease for the rest of their life and cannot be re-infected.

If the warts are so numerous or in a position where they are causing the dog quality-of-life issues, the veterinarian may choose to remove them surgically or by freezing them off. This will be done under with either a local or general anesthetic, depending on the location of the eruption. This is rarely necessary.

In some cases, the warts can get irritated and become infected. You veterinarian will prescribe an antibiotic and/or medicated wash to deal with the secondary infection, but this will not diminish the virus that causes the warts themselves.

During the time of “benign neglect,” you’ll want to watch your dog closely for any further signs of irritation or difficulty swallowing or breathing. If you notice this happening, you’ll want to schedule a follow-up visit with your veterinarian to discuss additional treatment options. Once the warts have completely disappeared, you should wait 2 more months before allowing your dog open contact with other dogs. After the incubation period of 2 months has passed with no new warts, your dog is assumed to be free of the virus, and now has immunity from contracting canine warts for the rest of their life.