Objective—To characterize clinical signs and histologic findings in dogs with odontogenic cysts and determine whether histologic findings were associated with clinical features.
Design—Retrospective case series.
Procedures—Medical records were reviewed to obtain clinical data, including breed, age, sex, and lesion location. Microscopic sections and results of diagnostic imaging were reviewed.
Results—Odontogenic cysts were identified in 41 dogs between 1995 and 2010. There were 29 dogs with dentigerous cysts, 1 with a radicular cyst, 1 with a lateral periodontal cyst, and 1 with a gingival inclusion cyst. In addition, 9 dogs with odontogenic cysts that had clinical and histologic features suggestive of, but not diagnostic for, odontogenic keratocysts seen in people were identified. In all 9 dogs, these cysts were located in the maxilla and surrounded the roots of normally erupted teeth. Of the 29 dogs with dentigerous cysts, 23 had a single cyst, 5 had 2 cysts, and 1 had 3 cysts. Six cysts were associated with an unerupted canine tooth, and 30 were associated with an unerupted first premolar tooth (1 cyst was associated both with an unerupted canine tooth and with an unerupted first premolar tooth). Dentigerous cysts were identified in a variety of breeds, but several brachycephalic breeds were overrepresented, compared with the hospital population during the study period.
Conclusions and Clinical Relevance—Results suggested that a variety of odontogenic cysts can occur in dogs. In addition, cysts that resembled odontogenic keratocysts reported in people were identified. We propose the term canine odontogenic parakeratinized cyst for this condition.
Objective—To characterize clinicopathologic features of the most common odontogenic tumors and focal fibrous hyperplasia (FFH) in dogs.
Design—Retrospective case series.
Animals—152 dogs evaluated for oral tumors of possible odontogenic origin at the William R. Pritchard Veterinary Medical Teaching Hospital of the University of California-Davis between 1995 and 2005.
Procedures—Information was collected from records, including dog breed, age, reproductive status, and location of lesion in the oral cavity. Histologic slides pertaining to each dog were reviewed by 3 investigators. Data regarding clinicopathologic features of the 3 most common lesions (canine acanthomatous ameloblastoma [CAA], peripheral odontogenic fibroma [POF], and FFH) were summarized.
Results—152 dogs with odontogenic tumors or FFH were identified. Sixty-eight (45%) dogs had CAA, 47 (31 %) had POF, 24 (16%) had FFH, and 13 (9%) had other odontogenic tumors. Canine acanthomatous ameloblastoma was present most commonly in the rostral aspect of the mandible, with POF and FFH more common in the rostral aspect of the maxilla. Males and females were equally represented among dogs with CAA and FFH. Castrated males were overrepresented among dogs with POF. Golden Retrievers, Akitas, Cocker Spaniels, and Shetland Sheepdogs were overrepresented among dogs with CAA. No breed predisposition was detected for FFH or POF. Dogs with FFH had a greater mean age at initial evaluation than did dogs with CAA or POF.
Conclusions and Clinical Relevance—CAA, POF, and FFH have distinct clinical patterns that may help clinicians and pathologists identify such lesions more readily.