Introduction The tear duct system in domestic cats ( Felis catus ), though small, plays a vital role in ocular health. Properly known as the nasolacrimal drainage system , it is responsible for draining excess tears from the eye’s surface into the nasal cavity. When this system malfunctions, it leads to visible and often treatable clinical signs, most notably epiphora (excessive tearing).

Tears produced by the lacrimal gland and the third eyelid’s gland normally lubricate the cornea, then drain through this pathway. In cats, this system is less curved than in dogs, making feline tear duct obstructions slightly less common but still clinically significant.

The system begins at the upper and lower puncta —tiny openings located at the inner corner (medial canthus) of each eyelid. These puncta lead to small canaliculi (ducts) that converge into the nasolacrimal sac , a small reservoir in the bony orbit. From there, a single nasolacrimal duct runs through the maxillary and lacrimal bones, opening into the nasal cavity just inside the nostril.