Introduction
Canine “warts” are actually benign growths caused by a number of species-specific and site-specific papilloma viruses. Dogs that develop solitary or clusters of warts may not need treatment. However, in some cases the growths become ulcerated, infected and painful, especially if they are scratched or chewed, and in other cases they can cause the dog mild to severe discomfort – particularly when they involve the toes and foot pads. If this happens, the papillomas should be removed. Sometimes, owners will elect to have the warts removed purely for cosmetic considerations.
Treating Warts on Dogs
Many oral mucosal and other papillomas are self-limiting and regress spontaneously without surgery once the dog mounts an appropriate immune response. If surgical removal is necessary or otherwise desired, it is normally accomplished by traditional excision, cryosurgery, laser ablation or electrosurgery/electrocautery.
Electrocautery essentially involves using electricity to burn off the affected tissue. This procedure often can be performed using a local anesthetic, so that the dog does not have to be intubated and put under general anesthesia. Cryosurgery involves freezing the growth, which also normally can be accomplished using a local anesthetic. Laser ablation is most often used for persistent cases involving large numbers of lesions, or those that are refractory to other treatment options, and usually requires general anesthesia.
Injectable subcutaneous interferon treatment, multiple times a week for up to 8 weeks, has been anecdotally reported to be helpful in cases of viral canine papillomas. Interferon can cause a number of unpleasant side effects, including fever, joint pain, nausea, inappetance and dizziness. A relatively new recombinant canine oral papillomavirus vaccine, developed by Georgetown University Medical Center, has shown promise as well. Other treatments are in development.
The prognosis for dogs with papillomas is generally good, especially since most cases regress on their own. It is possible, but highly unlikely, that papillomas can transform to malignant squamous cell carcinoma. Any lumps or bumps on our beloved companion dogs should be monitored and assessed regularly.