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What causes dog warts and how can you prevent them?

When we use the phrase “I love my dog, warts and all,” we’re typically referring to an undesirable trait we’re willing to overlook because our pooch is otherwise a very good boy. But what about literal warts? Whether your pup has always had a few warts, or you’ve noticed their appearance suddenly, dog warts are extremely common. So, what causes dog warts? Most importantly, should you be concerned about them? We’ll tell you what you need to know. 

A closeup shot of a black dog with a graying muzzle and a wart on his eyelid.

Should I worry if my dog has warts?

You might feel a surge of panic if your dog has been diagnosed with canine viral papillomatosis. But there’s no need to worry; that mouthful of a name is merely the medical term for dog warts. Caused by a form of the herpes virus, dog warts are benign tumors that usually won’t cause your pooch any distress. Canine papillomavirus normally has a 1-2-month incubation period, and it can be spread by direct contact with an infected animal or contact with shared items contaminated by the virus. 

For example, if your pup shared bedding or toys with a dog who has warts, it’s very likely he’ll also develop them. However, healthy, undamaged skin creates a barrier against the virus. According to the Mar Vista Animal Medical Center, “The virus requires injured skin to establish infection.” Even the smallest scratch or rash can leave your pup open to a viral infection, especially if he has a compromised immune system. 

But we have some good news: you can’t contract warts from your dog, and he can’t spread the virus to your family cat, either. In most cases, warts won’t cause any issues, but they can become infected if your dog bites or scratches at them. In very rare cases, some warts may be malignant

An English bulldog walks across a lawn.

Why is my dog getting more warts? 

While one or two small groups of warts can be easily ignored, you may have reason to be concerned if your pup develops a massive cluster of warts. Young puppies, senior dogs, and dogs with chronic health problems may have weaker immune systems, which puts them at an increased risk of large groups of warts. Your vet may remove the warts by surgically excising them, freezing them off, or using laser ablation therapy. However, most warts will disappear on their own within 2-12 months once your pup’s immune system has mustered a defense against canine papillomavirus. 

What causes old dog warts?

Canine papillomavirus is most common in young to middle-aged dogs, but it also affects dogs with compromised immune systems. Just like seniors are more likely to develop infections, older dogs are also at an increased risk. Your senior pup’s lowered immune system creates the perfect breeding ground for canine papillomavirus. 

When older dogs develop wart-like lumps, they aren’t always traditional warts. As dogs age, the normal cellular regeneration process changes, causing certain skin cells to grow at a rapid rate. This unusual growth rate often leads to benign skin growths that resemble warts. But that doesn’t mean you should ignore the sudden appearance of a wart-like growth on your beloved fur baby. 

Senior dogs have a higher chance of developing squamous cell carcinoma, a form of skin cancer often characterized by the appearance of firm, wart-like growths. You’ll usually spot these clusters on your dog’s head, hindquarters, lower legs, or abdomen, whereas viral warts usually occur on or near mucus membranes like the eyes and mouth. (In some cases, viral warts may also grow in clusters between your dog’s toes, on your dog’s eyelids, or even on the surface of the eye.)

A closeup shot of a senior chocolate brown lab with a graying muzzle.

What should I do if my dog has warts?

While you can easily purchase wart removal products for the annoying wart on your finger, we don’t recommend DIY wart removal for your dog. Instead, we advise you to schedule a visit with the vet. In most cases, your dog’s warts can be left alone. But if your pup’s warts are causing problems, you should leave treating them in your vet’s hands. In addition to removing the warts, your vet may biopsy them or recommend immune-boosting drugs like Interferon

If you have multiple dogs, you’ll need to keep your pup quarantined while he has an active infection. Don’t allow your dogs to share bedding, food and water bowls, or toys while the infection is present. If possible, don’t take your pup to dog parks or board him while he has an active infection, as he could expose immunocompromised dogs. Remember, when in doubt, consult your vet on how best to manage your dog’s condition.

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