Clinicopathologic study of 174 epuli in dogs

Epulis is a clinical term that has longed been used to diagnose gingival lesions occurring in dogs. Attempts have been done to individualize these lesions, and classifications have been proposed, some of which attempt to correlate dog lesions to those occurring in humans. Studies have shown that although some resemblance does exist, the lesions tend to be different in histologic aspects and clinical behavior. Among these lesions, most are of odontogenic origin or hyperplastic reactive lesions. Histologic characteristics of 174 oral dog tumors with clinical appearance of epulis were reviewed. The lesions originally diagnosed as fibromatous, acanthomatous, and ossifying epulis were reclassified taking the currently available criteria into account. The lesions most frequently diagnosed were peripheral odontogenic fibroma (53.5%), fibrous hyperplasia (32%), peripheral ameloblastoma (11.5%), and odontoma (3%). The average ages of dogs presenting focal fibrous hyperplasia, peripheral odontogenic fibroma, and peripheral ameloblastoma were 8.7, 7.7, and 7 years, respectively, and for odontomas the median age was 5 months. There were slight breed differences among the types. Only in peripheral odontogenic fibroma, males were more affected than females. The other tumors were equally frequent in males and females. Because clinical behavior and management vary among the oral lesions, it is important to properly diagnose them.