Paranasal Sinusitis – A Long-term Clinical Study of 200 Cases (1997-2009)

Sinusitis, mainly due to bacterial infection, is the most common cause of unilateral nasal discharge in the horse and can have multiple initiating causes. Primary sinusitis is classified as such if there is no underlying reason found for the development of sinusitis – the aetiology of primary sinusitis is thought to be upper respiratory infection which initiates generalised inflammation of multiple sinuses, blockage of the sino-nasal ostium and bacterial infection of accumulated intra-sinus secretions with later possible inspissation of exudate within sinuses in chronic cases. Acute primary sinusitis normally clears spontaneously with remission of the respiratory infection, with just a minority of cases developing a chronic primary sinusitis (>2 months duration) in one or more sinuses, especially within the rostral maxillary and ventral conchal sinuses. Cases of sinusitis can also be secondary to other disorders including; apical infections of the caudal maxillary cheek teeth or dental related oro-maxillary fistulas; sinus cysts; sinus neoplasia; mycotic sinus infections; intra-sinus progressive ethmoidal haematomata and sinus trauma. […]