Congenital Nasolacrimal Atresia in an Arabian Horse

Introduction
Nasolacrimal duct obstruction is a blockage of the lacrimal drainage system. obstruction of the nasolacrimal outflow pathway in horses is not uncommon. Causes of obstruction include foreign bodies, trauma, and congenital abnormalities1.

Aim of the study
In this paper we describe the clinical manifestations, diagnosis, and treatment of congenital nasolacrimal duct atresia (nasal punctal atresia) in an arabian horse.

Material & Methods
A 3-year-old arabian mare was presented with a life-long history of purulent discharge from the left eye. ocular examination revealed marked epiphora and mucopurulent conjunctival discharge. the examination was completed following pharmacological mydriasis with 0.5% pro-paracaine hydrochloride. following application of pro-paracaine, nasolacrimal lavage was completed by cannulation of the upper nasolacrimal puncta with a 24 gauge × 3/4 inch intravenous catheter and flushing with 10 ml of sterile saline. Dacryocystorhinography was completed following administration of xylazine (0.5 mg/kg of body weight). approximately 4 mL of renografin-60 (Diatrizoate meglumine injection uSp) was injected through the upper cannula and lateral and oblique radiographs were completed.

Results & conclusion
Dacrocystorhinography accurately revealed an obstruction of the left distal portion of the nasolacrimal duct of suspected congenital origin (i.e., atresia). the nasolacrimal obstruction was treated by creating a new drainage opening by an incision in the nasal mucosa inside the nostril with placement of a stent for 3 weeks. post-operative therapy consisted of topical antibiotic/corticosteroid combination, (gentamicin /dexametha- sone), q12h for 3 weeks, then q24h until stent removal. in this case, there was no evi- dence of nasolacrimal obstruction noted after surgery2-4.