An 18-year old jenny was observed with a right maxillary tumefaction, presenting weight loss, quidding, dysphagia and halitosis. An external and intra oral examinations were performed. Both exams revealed a complete blockage of motion in the right mandible, due to the presence of severe shear mouth. A pedunculated mass was observed in the right maxillary vestibular space. It was speculated that the mass resulted from food debris acting as a source of gingival irritation, as a consequence of the shear mouth.
Gingival hyperplasia is a common histological feature in equids, due to close contact between an abrasive diet and oral tissues. However, on a macroscopic level, pathological proliferation of the gingival tissue is uncommon and seldom reaches significant dimensions, but still should be considered differential diagnoses when examining an equid with pertinent clinical signs, mainly when severe dental disorders are diagnosed.
This clinical case seems to be the first describing the occurrence of gingival fibrous hyperplasia apparently as a direct consequence of shear mouth in a donkey.