Equine paranasal sinus disease: a long-term study of 200 cases (1997-2009): treatments and long-term results of treatments.

Reasons for Performing Study: There is limited objective information available on the treatment and the long-term response to treatment of the different types of equine sinus disease.
Objectives: To document the treatments and long-term response to these treatments in 200 cases of equine sinus disease (1997-2009).
Methods: The treatments of horses affected with subacute primary sinusitis (n = 52); chronic primary sinusitis (n = 37); dental sinusitis (n = 40); sinus cyst (n = 26); traumatic (n = 13); dental-related oromaxillary fistula (n = 8); sinus neoplasia (n = 10); mycotic sinus disease (n = 7); and intrasinus progressive ethmoid haematoma (n = 7) and the long-term response to these treatments were retrospectively reviewed.
Results: Treatments evolved throughout the study and latterly were as conservative as possible, including sinoscopic lavage and standing sinusotomy, with a maxillary sinusotomy approach preferred for the mainly mature horses treated in this study. Removal of intrasinus inspissated pus, including transendoscopically (by sinusotomy and via existing sinonasal fistulae), was the main treatment for chronic primary sinusitis and sinonasal fistulation was seldom performed latterly. Attempted oral extraction of infected cheek teeth, even if unsuccessful, facilitated subsequent dental repulsion, resulting in few post operative problems. Sinus cyst removal carried an excellent prognosis. Except for cases of sinus neoplasia (only 22% cured), an excellent long-term response to treatment (91% fully cured, 7% partially cured) was obtained for all other types of sinus disease following a median of one treatment.
Conclusions: More conservative treatments, including removal of intrasinus inspissated pus by sinoscopy, pre-existing sinonasal fistula or sinusotomy, are effective for chronic primary sinus disease. Standing sinusotomy, mainly using a small maxillary site, was suitable for most cases of sinus disease in mature horses.
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