Abstract: Brachycephalic Ocular Syndrome (BOS) encompasses ophthalmic disorders associated with brachycephalic breeds, including exophthalmos, lagophthalmos, macropalpebral fissure, medial entropion, trichiasis, nasal fold trichiasis, corneal ulceration, pigmentary keratitis, tear film abnormalities, and progressive vision loss. This study evaluated 500 brachycephalic dogs at Madras Veterinary College for BOS, with detailed ophthalmic assessment including scleral ‘show’, eyelid closure, palpebral fissure measurement, entropion grading, nasal fold thickness, Schirmer tear tests (STT I and II), tear break-up time (TBUT), and corneal mapping. Out of 382 dogs with BOS, Pugs were the most affected breed (92.8%). Pigmentary keratitis (39.29%) and medial entropion (31.94%) were most frequent, with tear film deficiency predisposing dogs to ocular surface disease. Findings indicate a strong correlation between eyelid conformation abnormalities, nasal fold trichiasis, and corneal pathology. Early surgical intervention and tear film management are crucial for halting progressive corneal damage and preserving vision in affected dogs.
