Home » Pet Health » Canine Viruses and Infections » How Does CPV Spread, and Prevention


CPV spreads through direct dog-to-dog contact. Transmission can happen when dogs greet each other or when they share the same food dish, water bowl, or toys. The virus most commonly affects dogs still in the puppy phase, typically two years of age and younger. A younger dog’s immune system is still developing and cannot fight off the virus effectively. If your dog is on immunosuppressive medication, such as cyclosporine, it is also more likely to contract CPV and have an outbreak of viral warts. However, once your dog develops the antibodies to fight off the virus, they cannot get the same strain again. Nevertheless, there are many different CPV strains, and they may contract a different one.

CPV Diagnosis 

Because of the unique appearance of the CPV wart, it is typically easy to diagnose on sight by a vet. These viral growths commonly grow in groups, so if you find one wart, check your dog’s lips or inside their mouth for more. Because there has been some evidence that CPV may lead to certain kinds of cancer, your vet may wish to take a biopsy to ensure the lesion is not cancerous.

If you notice warts on your dog, it is still essential to take them to the vet, as there are other health problems commonly mistaken for CPV when assessed by an untrained eye.

Treatment of CPV

Fortunately, canine papillomas usually resolve after 2 to 3 months with little medical intervention because your dog’s immune system develops antibodies against the virus and fights it off. Although papillomas are not dangerous or painful, sometimes they need to be surgically removed. Suppose the papilloma becomes infected, interferes with eating or swallowing, or fails to go away after a particular time. In that case, your vet may recommend minor surgery to remove the wart. If the vet removes the wart too early, your dog may not have had enough time to become immune, and another wart might appear. Therefore, the vet will give your dog’s body ample time to fight off the virus on its own if possible.

There are some additional treatment options you may wish to discuss with your vet. In severe cases, anti-viral doses of interferon might be used to treat CPV. But it is generally not recommended, as it is expensive for the pet owner and does not always help. A new medication, called imiquimod, is also available and is increasingly used to treat papillomas. Talk to your vet to see if these options suit you and your dog.

How can I prevent CPV infections? 

Generally, preventing CPV infections is very difficult, especially if your dog is social and active. The best way to avoid CPV infections is to keep your dog’s immune system healthy and strong with nutritious food, regular exercise, and a stress-free environment.

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Last Updated: September 16, 2022

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The following sources were referenced to write the content on this page:

Chang, C-Y, Chen, W-T, Haga, T, Yamashita, N, Lee, C-F, Tsuzuki, M & Chang, H-W 2020, ‘The detection and association of canine papillomavirus with benign and malignant skin lesions in dogs’, Viruses, vol. 12, no. 2, pp. 170.

Ghim, S, Newsome, J, Bell, J, Sundberg, JP, Schlegel, R & Jenson, AB 2000, ‘Spontaneously regressing oral papillomas induce systemic antibodies that neutralize canine oral papillomavirus’, Exp Mol Pathol, vol. 68, no. 3, pp. 147-151.

Munday, JS 2021, Animal Papillomaviruses (Papillomaviridae), Encyclopedia of Virology, 4 edn, Elsevier.

The Pet Cancer Foundation’s medical resource for pet owners is protected by copyright.

For reprint requests, please see our Content Usage Policy.