Dog Warts: What They Are, Why They Appear, and How to Help Your Dog

Discovering a strange bump or growth on your dog can send any pet parent into a tailspin of worry. If you’ve noticed small, rough, cauliflower-like lumps on your dog’s skin or around their mouth, there’s a good chance you’re looking at dog warts — and while the name alone might make you cringe, the good news is that they’re usually harmless. Understanding what these growths are, where they come from, and when to act can help you feel confident and informed every step of the way.

Common Causes

Dog warts, known medically as canine viral papillomas, are caused by the canine papillomavirus (CPV). This contagious virus spreads through direct contact with an infected dog or contaminated surfaces such as shared water bowls, toys, and bedding. The virus targets the outer layer of the skin, causing abnormal cell growth that results in the wart-like lesions most pet owners recognize.

There are actually multiple strains of the canine papillomavirus, and each tends to favor specific locations on the body. CPV-1 is the strain most commonly responsible for oral papillomas — the clusters that appear around the mouth, lips, and tongue in younger dogs. Other strains are more likely to produce solitary skin warts on the legs, belly, or eyelids. This is why two dogs with “warts” can look quite different from one another, even when the underlying cause is identical. A veterinarian can often identify the likely strain based on location alone, though definitive diagnosis may involve a biopsy or PCR testing in ambiguous cases.

Age plays a meaningful role in how and when the virus takes hold. Puppies between six months and two years old are the most commonly affected group, simply because their immune systems haven’t yet built up the defenses needed to fight off viral infections efficiently. On the flip side, senior dogs whose immunity has declined with age can also be vulnerable, sometimes developing warts that are more persistent or widespread than what you’d see in a healthy young adult dog. There doesn’t appear to be a strong seasonal pattern to papillomavirus outbreaks, but cases often cluster around times of high dog-to-dog contact — think summer dog park season or the busy boarding periods around holidays.

It’s worth noting that not every dog who encounters the virus will develop warts. A dog’s immune response plays a significant role in determining whether the papillomavirus takes hold. Several factors can increase the likelihood of your dog developing warts:

• Young or underdeveloped immune systems — Puppies are particularly susceptible because their immune systems are still maturing.
• Immunocompromised dogs — Older dogs or those undergoing treatments such as chemotherapy or long-term steroid use are at higher risk.
• Frequent dog-to-dog contact — Dogs who visit dog parks, boarding facilities, grooming salons, or doggy daycare have greater exposure to the virus.
• Environmental exposure — The papillomavirus can survive on surfaces for extended periods, making indirect transmission entirely possible.
• Minor skin injuries — Small cuts or abrasions can make it easier for the virus to enter and infect skin cells.

Most warts caused by the papillomavirus will resolve on their own as your dog’s immune system mounts a response, typically within one to five months.

Symptoms to Watch For

Canine warts have a fairly distinctive appearance once you know what to look for. They most commonly develop around the mouth, lips, and tongue, though they can also appear on the eyelids, between the toes, and on other areas of the skin. Because they can vary in size and location, it’s helpful to know exactly what to look for during your regular at-home checks.

Common symptoms and signs associated with dog warts include:

• Rough, bumpy growths that resemble a small head of cauliflower or a tiny piece of coral
• Single or clustered lesions appearing around the lips, gums, tongue, or throat
• Skin warts on the paws, belly, or around the eyes
• Difficulty eating or swallowing if warts are present inside the mouth or throat
• Pawing at the mouth or face, which may indicate oral discomfort
• Bleeding or irritation if a wart has been scratched, bitten, or traumatized
• Bad breath that develops alongside oral warts due to secondary bacterial involvement

In most cases, warts don’t cause your dog significant distress. However, large clusters in the mouth can occasionally interfere with eating, and any wart that bleeds, grows rapidly, or changes in appearance deserves prompt veterinary attention.

Symptom Severity at a Glance

Symptom	Risk Level	Action Required
Small, stable wart with no irritation	Mild	Monitor at home; recheck weekly
Bad breath alongside oral warts	Mild	Mention at next routine vet visit
Pawing at mouth or face	Moderate	Call your vet within 24–48 hours
Difficulty eating or swallowing	Moderate	Schedule a vet appointment promptly
Bleeding or ulcerated wart	Serious	Contact your vet within 24 hours
Rapid increase in wart size or number	Serious	Call your vet today
Single firm, raised lump with irregular edges	Serious	Seek veterinary evaluation immediately

Breeds Most at Risk

While any dog can develop papillomavirus warts, certain breeds appear more frequently in veterinary literature due to immune system tendencies or anatomy that creates favorable conditions for the virus.

Cocker Spaniels have a well-documented predisposition to a range of skin conditions, and their immune systems can be somewhat less aggressive in clearing viral infections. They are more likely to develop persistent or recurrent warts compared to many other breeds, and their cases sometimes require veterinary intervention rather than resolving on their own.

Shar-Peis are known for having naturally compromised immune function and a unique skin structure — their deep folds and loose skin create warm, moist environments where the papillomavirus can establish itself more easily. These dogs are also prone to a variety of skin-related health issues in general, making routine skin checks especially important for this breed.

Miniature Schnauzers are frequently cited in dermatology literature for their susceptibility to viral skin conditions, including papillomas. Their tendency toward immune dysregulation means they may take longer than average to clear an infection, and they can sometimes develop multiple warts simultaneously rather than just one or two.

If your dog is one of these breeds and you notice any unusual skin growth, it’s worth having it evaluated sooner rather than later.

What You Can Do at Home

In many cases, the most effective thing you can do at home is simply monitor the warts and give your dog’s immune system the time and support it needs to clear the infection on its own. That said, there are several practical steps you can take to keep your dog comfortable and prevent the virus from spreading to other pets in your household.

First, avoid letting your dog share water bowls, food dishes, or toys with other dogs until the warts have fully resolved. The papillomavirus is contagious between dogs, so limiting contact with shared items is an easy and important precaution. Regularly disinfecting your dog’s belongings during this period is also a good habit.

Second, resist the urge to squeeze, pick at, or attempt to remove the warts yourself. Doing so can cause pain, introduce a secondary infection, and potentially spread the virus further. The warts may look bothersome, but they need to run their course naturally in most situations.

Supporting your dog’s overall immune health can also make a difference. Make sure your dog is eating a balanced, high-quality diet, getting regular exercise, and staying up to date on routine veterinary care. A strong immune system is your dog’s best defense against the papillomavirus and many other health challenges.

Finally, keep a close eye on the warts and take photos periodically. This makes it much easier to track any changes in size, number, or appearance and gives your vet a helpful reference point if you decide to seek professional guidance.

When to See a Vet

While most dog warts are benign and self-limiting, there are situations where a veterinary visit is the right call. You should schedule an appointment if:

• The warts are not resolving after two to three months
• Your dog is having difficulty eating, drinking, or swallowing
• A wart is bleeding, ulcerated, or has changed rapidly in appearance
• The growths are spreading quickly or increasing in number
• Your dog seems to be in pain or is persistently pawing at their face
• You notice a single firm, raised lump that doesn’t look like a typical papilloma

It’s also worth having any new skin growth evaluated if you’re unsure of what you’re dealing with. Not all lumps and bumps are warts — some can be benign cysts or skin tags, while others may warrant further investigation. Your veterinarian can examine the growth, confirm the diagnosis, and recommend treatment if necessary. In some cases, your vet may suggest surgical removal, cryotherapy (freezing), or antiviral medications to help resolve stubborn or problematic warts.

Never attempt to diagnose your dog based on appearance alone. When in doubt, always consult a professional.

How Pet Insurance Can Help

Veterinary care for warts is often straightforward, but costs can add up quickly — especially if treatment involves removal, anesthesia, or follow-up visits for complications. Having a solid pet insurance plan in place means you can make decisions based on what’s best for your dog rather than what’s most affordable in the moment. Being prepared before an unexpected health issue arises is one of the kindest things you can do for your pet.

Protective Care: Get a free pet insurance quote and protect your dog today

For times when you need immediate guidance from a licensed veterinarian without leaving home, telehealth services can be a lifesaver.

For more clinical details on canine health, you can refer to the professional guidelines from the Merck Veterinary Manual.

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Finding a strange growth on your dog is understandably unsettling, but dog warts are one of the more manageable health issues your pup can face. With a watchful eye, a little patience, and the support of your veterinary team when needed, most dogs recover completely without any lasting issues. You’re clearly already doing the right thing by taking the time to learn — and that kind of attentive care makes all the difference for your dog’s well-being.