Rostral hard palate swelling (lampas) in horses: true or fiction?

This study aimed to determine the occurrence of swellings (lampas) in the rostral portion of the hard palate in young, adult, and elderly horses and to characterize them histologically. One hundred and twenty horses of different ages were evaluated by oral inspection. Horses were classified with lampas when the mucosa of the hard palate extended beyond the occlusal surface of the upper incisors and samples of palatal mucosa were collected. Ten other horses without rostral hard palate alterations, euthanized for unrelated causes, were included as the control group. Histological analysis included thickness of lamina propria and keratinized epithelium. Of the animals examined, 23 % (28/120) showed swellings of the rostral hard palate; in one case there was mucosal hyperplasia, and no histological evidence of inflammation was observed in the samples analyzed. There were no differences in thickness between young, adult, and elderly animals with swelling and the control group (p > 0.05). These findings suggest that such swellings may be frequently misinterpreted clinically, as surgical intervention may result in temporary improvement of stereotypies rather than a true resolution. The absence of inflammation supports the interpretation that these changes may represent anatomical variation or adaptive responses, and surgical excision appears rarely justified.