Warts (Papillomatosis) in Dogs

Key Takeaways

Papillomatosis, also known as warts, is an infection caused by papillomavirus in dogs.

• Presents as benign skin tumors (warts) most commonly in the oral cavity and lips, but can affect any part of the skin

• Dogs become infected with papillomavirus through direct contact with another infected dog

• Various types of papillomavirus can affect all animals, including humans, although they are highly species-specific

• Papillomas are often diagnosed through a routine physical examination, although other tests may include cytology and/or biopsy

• Treatment is rarely required as papillomas often resolve spontaneously after a month or two

• Persistent warts might need surgical removal or cryotherapy (freezing with liquid nitrogen), but overall papillomatosis has a good prognosis

A Closer Look: What is Papillomatosis in Dogs?

Papillomas, or warts, are benign tumors caused by a viral infection in dogs. They are usually harmless, but many other skin conditions present similarly to warts so a correct diagnosis is necessary before deciding to forgo treatment.

Risk Factors

In some cases, warts might ulcerate and bleed. Some forms of papillomas grow inwards, which might cause discomfort and pain, especially on the feet or in the mouth. 

Large warts inside the mouth can become extremely painful and even affect normal chewing. Papillomas might develop secondary skin infections in severe cases. 

Papillomas, or warts, are very common in dogs. In most cases, the tumors disappear on their own. Surgical or cryothermal removal is only necessary if warts become infected, inflamed, or too numerous. Puppies are particularly susceptible to infection.

Possible Causes

Warts are caused by a papillomavirus infection. 

Dogs can get infected through contact with a contagious dog or through their environment (water bowl, food).

The virus enters the body through cuts and abrasions, or from biting insects including ticks, fleas, and mosquitoes.

Main Symptoms

Warts are self-evident, and may arise in different patterns and locations on the body. Papillomas may present as multiple or solitary wart-like masses. They are commonly found in the oral cavity and lips, but can also be found on the eyelid, conjunctiva, or genital region. 

Warts may present with different characteristics: they can be round and smooth, like human warts, or present with a scaly, cauliflower-like aspect. Papillomas may also appear as dark, flat masses on the skin.

Testing and Diagnosis

Most warts have a typical appearance and can be diagnosed through a routine physical examination. To confirm the presumptive diagnosis, cytology and/or biopsy is required.

Steps to Recovery

Most papillomas do not need treatment as they usually resolve spontaneously. If the tumor does not disappear on its own, if there are many tumors, or if it is causing pain or discomfort, the usual treatment is surgical removal. Another tumor removal option is cryogenic therapy (freezing the wart with liquid nitrogen). In severe cases, if the tumor leads to a secondary skin infection, antibiotics may be necessary.

Most papillomas usually start regressing on their own after one or two months. Oral cavity papillomas might take more time, usually three months or longer. Persistent tumors may need to be surgically removed, but the overall prognosis is good.

Prevention

Papillomas are contagious. Transmission happens through dog-to-dog contact or through contact with a contaminated object (such as water bowls or toys). Papillomavirus can survive in extreme environments. Prevention is often difficult as some carriers might be asymptomatic. Some form of papillomavirus exists for all species, including humans, but the virus is species-specific so transmission between dogs and other species is not possible.

Is Papillomatosis Common in Dogs?

Papillomas are common, especially in puppies.

Typical Treatment

• Benign neglect

• Surgical removal

• Cryogenic removal

• Antibiotics