Causes
Canine papillomavirus, contagious between dogs. More common in young dogs whose immune system is still immature.
Diagnosis
Visual diagnosis. If there is any doubt, a biopsy.
Treatment
Most disappear on their own within weeks or a few months once the immune system responds. They are only removed if they cause discomfort, bleed or make eating difficult.
Prevention
Not preventable. Avoid contact with dogs that have active warts if your own dog is young.

