Treatment of Canine Generalized Papillomatosis with Vincristine Sulfate and Levamisole: Case Report
C.E.T. Caires; M.I.F. Caldeira; C.B. Campos; R.A. Carneiro; F.N. Machado
Papillomatosis is a benign neoplasm originated from squamous epithelium, common in dogs and rare in cats. The disease is induced by papillomavirus, contagious and species specific. An injury in the epithelium is necessary for the virus to infect basal keratinocytes of the stratum germinativum and induce replication of its genome associated to the cell`s DNA. Tissue response to viral infection is an increase in mitotic activity, resulting in acanthosis and hyperkeratosis. In young dogs less than a year old, lesions usually occur on the head, eyelids, mouth, lips, tongue, pharyngeal mucosa, paws. Incidence is not associated with sex or breed. In adult dogs, isolated nodes can develop on the head, eyelids and genital areas (differential diagnosis with transmissible venereal tumor--TVT). Papillomatosis frequently manifests as multiple pedunculated masses (with diameter up to one centimeter), similar to a cauliflower or skin, mucosa or mucocutaneous warts. In order to confirm diagnosis papillomas should be biopsied. Papillomatosis can be self-limiting, but if spontaneous regression does not occur or if it presents multiple growths with persistence of clinical signs, treatment is indicated. Ptyalism, halitosis and oral discomfort can be clinical signs. After recovery the animal is immune to reinfection. This study aims to report an alternative clinical treatment in an one year old Shar-pei that presented multiple papillomas on the cornea, oral cavity, face and pectoral, limbs and inguinal region. Due to the extent of the lesions, surgical excision was impracticable. Treatment protocol was six weekly sessions of vincristine sulfate at 0.75mg/m2 given intravenously, levamisole at 2mg/kg given orally every 48 hours; antibiotic therapy with spiramycin and metronidazole at 1mg/kg every 24 hours, during ten days. Clinical evaluation and complete blood count were performed before every session, for control and follow-up of the patient. Regression of the symptoms was gradual, with satisfying results after treatment.