Cat Blocked Tear — Duct [2021]

Feline Nasolacrimal Duct Obstruction: Etiology, Clinical Presentation, Diagnosis, and Management

The gold standard diagnostic test. A drop of fluorescein dye is placed in the conjunctival sac. Under normal conditions, dye should appear at the ipsilateral nostril within 5–10 minutes. Failure to observe dye suggests complete obstruction. Delayed transit (>20 minutes) indicates partial obstruction. cat blocked tear duct

A 4-year-old Persian cat presented with chronic left-sided brownish ocular discharge. Schirmer tear test and corneal staining were normal. Fluorescein dye failed to reach the left nostril after 15 minutes. Nasolacrimal flushing with saline encountered mild resistance, followed by reflux of mucoid debris. No foreign body or mass was seen on skull CT. The cat was diagnosed with chronic idiopathic partial obstruction. Treatment consisted of weekly ductal flushing under sedation and topical antibiotic-steroid ointment for 4 weeks, resulting in decreased discharge. The owner was advised of possible recurrence. Failure to observe dye suggests complete obstruction

Using a lacrimal cannula (e.g., 24-26 gauge), sterile saline is gently flushed through the superior punctum. Patency is confirmed if fluid flows freely from the nostril. Resistance or reflux from the same punctum indicates obstruction. Schirmer tear test and corneal staining were normal

Feline nasolacrimal duct obstruction is a manageable yet often chronic condition that requires a systematic diagnostic approach. The fluorescein dye transit test and ductal flushing remain essential diagnostic and therapeutic tools. Clinicians should differentiate congenital (breed-associated) from acquired (inflammatory, neoplastic, traumatic) causes to guide prognosis and treatment. While medical management suffices for mild cases, surgical bypass is available for severe, refractory obstructions. Further research into the role of viral rhinitis in chronic feline NLDO would improve long-term management strategies.

Nasolacrimal duct obstruction (NLDO), commonly referred to as a blocked tear duct, is a relatively common ophthalmic condition in domestic cats. The nasolacrimal duct system is responsible for draining tears from the ocular surface into the nasal cavity. When this system becomes obstructed, epiphora (excessive tearing) results, often leading to periocular dermatitis, cosmetic concerns, and in some cases, secondary infection. This paper reviews the anatomy of the feline nasolacrimal system, the various etiologies of obstruction (congenital and acquired), diagnostic techniques including the fluorescein dye transit test and dacryocystorhinography, and current medical and surgical management strategies. A focus is placed on breed predispositions, particularly in brachycephalic cats, and the importance of ruling out underlying causes such as neoplasia or chronic rhinitis.