Treatment of oromaxillary fistulae in nine standing horses (2002-2006)

REASONS FOR PERFORMING STUDY: There is minimal published information on equine oromaxillary fistulae that are unrelated to cheek teeth (CT) repulsion or on the conservative treatment of these atypical fistulae. OBJECTIVES: To report equine oromaxillary fistulae unrelated to CT extraction and describe their management in standing horses. METHODS: Case details of oromaxillary fistulae of atypical aetiology occurring at 2 referral centres between 2002-2006, including their treatment and response to treatment were examined. RESULTS: Nine cases of oromaxillary fistula were recorded, mainly in aged horses (median 22 years). Fistulae were associated with CT diastemata in 7 cases, fractured CT in one and a central defect in a worn CT in another. After removing food and exudate from the sinuses, 6 cases were treated successfully by filling the diastema or dental defect with polymethylmethacrylate (PMMA). Following dental extraction, the other 3 cases were treated successfully by use of PMMA alveolar packing. CONCLUSION: Older horses can spontaneously develop oromaxillary fistulae, usually secondary to CT diastemata. In the absence of apical infection, this disorder can usually be treated successfully in standing horses by treating the sinusitis and sealing the oral aspect of the diastema with PMMA. POTENTIAL RELEVANCE: Older horses with sinusitis should be assessed for the presence of CT diastemata and oromaxillary fistulae. If detected, these disorders can be treated successfully in the standing horse.