AbstractObjectiveTo describe the use of an endoscope to assist in performing minimally invasive dacryocystorhinostomy in a dog to successfully manage a nasolacrimal duct cyst (dacryocyst).Animal StudiedA 4‐year‐old female spayed American Staffordshire Terrier with chronic epiphora and swelling ventromedial to the nasal canthus of the right eye and reverse sneezing.ProceduresComputed tomography revealed a fluid‐filled cystic lesion of the right nasolacrimal duct with extensive nasal extension and secondary obstructive frontal sinusitis. Aspiration of serosanguinous fluid with no growth of microbial organisms and histopathology confirmed the cystic nature of the structure. A 2.7 mm, 30 deg, 11 cm foreward‐oblique endoscope with arthroscopic cannula was passed through a mucosal stab incision in the dorsal buccal recess into the cyst to allow for exploration. A separate instrument portal was placed in the center of the cyst through the skin which allowed for transcutaneous dacryocystorhinostomy with a meniscal probe to be performed. No clear communication was evident caudodorsally into the frontal sinus on endoscope examination. A small frontal sinus trephination was performed and lavage flowed easily into the cystic cavity and out of the nostril.ResultsFollow‐up at 10 days and 17 months postoperatively showed complete resolution of clinical signs with an excellent cosmetic outcome.ConclusionEndoscopy‐assisted dacryocystorhinostomy demonstrated an effective minimally invasive technique to treat a functionally obstructive dacryocyst of the right nasolacrimal duct in a dog.