Efficient Topical Treatment of Canine Nodular Sebaceous Hyperplasia with a Nitric Acid and Zinc Complex Solution

Nodular sebaceous gland hyperplasia in the often middle-aged to old dog is a common, benign proliferation that results in exophytic, pink to yellow, alopecic, and often multilobulated nodules. Removal is usually carried out by surgical excision. As many old dogs have comorbidities that increase the risk of anesthesia, a topical treatment is warranted. We hypothesized that the application of a solution containing nitric acid, zinc, copper, and organic acids (Verrutop®), would be a safe and efficient way to treat these nodules. Eleven dogs with a total of 29 nodules, grossly compatible with nodular sebaceous gland hyperplasia, were included in the study. Eighteen of the nodules were treated; 11 were left untreated. No anesthesia or sedation was needed. Four weeks after one application, 17/18 treated nodules had decreased by 100% in volume. There was a statistically significant difference in percentual volume change between the treated and untreated nodules from day 0 to day 28 (p < 0.0001). No serious side effects were noted. Sebaceous hyperplasia cannot always be distinguished grossly from sebaceous tumors. Cytological evaluation can be helpful, and in cases of deviant macroscopic features, local recurrence, or more aggressive behavior, the appropriate intervention would be to biopsy or excise the nodule for histopathology. Topical application of Verrutop® is an easy, low-cost, and efficient way to remove canine sebaceous gland hyperplasia with minimal side effects in cases where surgery and anesthesia are not desired.