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.
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. cat blocked tear duct
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. The gold standard diagnostic test
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
Feline Nasolacrimal Duct Obstruction: Etiology, Clinical Presentation, Diagnosis, and Management