Disorders of the Paranasal Sinuses

Inflammation of the equine paranasal sinuses is a relatively uncommon disease that may be caused by primary bacterial or mycotic infections (Mason 1975a), or can be secondary to dental disease (van der Velden & Verzijlenberg 1984, Scott 1987, Tremaine & Dixon 2001a), facial trauma, sinus cysts, progressive ethmoid hematoma or sinonasal neoplasia (Mansmann & Wheat 1973, Gibbs & Lane 1987, Tremaine & Dixon 2001a). Equine sinusitis is usually unilateral but bilateral disease has been reported (Coumbe et al 1987, Lane 1993, Tremaine & Dixon 2001a). There is apparently no breed, age or gender predisposition to sinusitis. Clinical signs of any type of sinusitis usually include unilateral purulent nasal discharge, ipsilateral submandibular lymph node enlargement, and epiphora. Less common signs include facial swelling, exophthalmos, abnormal respiratory noises, head shaking, and exercise intolerance (Lane 1993, Tremaine & Dixon 2001a).