In 2002, some dogs with chronic papillomas of the footpad that exhibited histologic features characteristic of papillomavirus infection were discovered. In some cases, the dogs had been vaccinated against COPV, suggesting that another type of canine papillomavirus might be the etiologic agent. These footpad lesions were also much more persistent than COPV lesions, in some cases lasting more than 6 months. Usually the footpad lesions were associated with a clinical history of immunosuppression or with a stressful environmental setting. To determine whether there was a new canine papillomavirus associated with this disease, the virus was cloned, sequenced and characterized. The new virus was desinated as Canis familiaris papilloma virus type 2 (CfPV-2). More recently it is renamed as CPV2.