A retrospective study of lingual lesions in 793 dogs and 406 cats at the Athens Veterinary Diagnostic Laboratory, 2010-2020.

Lingual biopsies are a common type of sample submission at the Athens Veterinary Diagnostic Laboratory (AVDL). Here we describe the pathology diagnoses of 793 canine and 406 feline lingual biopsies submitted to the AVDL in a 10-y period. Non-neoplastic lesions accounted for 450 diagnoses (57%) in dogs and 239 diagnoses (59%) in cats. Canine non-neoplastic lesions consisted of inflammatory lesions (286 cases; 64% of non-neoplastic lesions) and tumor-like proliferative lesions (164 cases; 36% of non-neoplastic lesions). Feline non-neoplastic lesions consisted of inflammatory lesions (228 cases; 95% of non-neoplastic lesions) and tumor-like proliferative lesions (11 cases; 5% of non-neoplastic lesions). The most common canine neoplasms were melanocytic neoplasms (103 cases; 30% of neoplasms) and epithelial neoplasms (102 cases; 30% of neoplasms), followed by mesenchymal neoplasms (90 cases; 26% of neoplasms) and round cell neoplasms (48 cases; 14% of neoplasms). Approximately 43% of melanocytic neoplasms affected Chow Chows and Labrador Retrievers, and 20% of epithelial neoplasms affected Labrador Retrievers. In cats, most tumors were epithelial (158 cases; 94% of neoplasms), followed by mesenchymal (8 cases; 5% of neoplasms) and round cell neoplasms (1 case; 1% of neoplasms). Over 50% of neoplasms of cats affected domestic shorthair cats. Although the percentage of lingual biopsies that had a neoplastic diagnosis was roughly the same between species, the diversity of neoplasms was much greater in dogs than in cats.