Contrast computed tomography dacryocystorhinography identifies nasolacrimal duct obstruction secondary to chronic dental disease in two chinchilla langeria.

Objective: To determine the impact of chronic dental disease on the nasolacrimal duct of chinchillas using contrast CT dacryocystorhinography.

Animals studied: Two 12-year-old female chinchillas with uni- or bilateral ocular discharge and a history of chronic, moderate (Chinchilla 1, one-year) or severe (Chinchilla 2, three-years) dental disease.

Procedures: Contrast CT dacryocystorhinography was performed to identify abnormalities in the nasolacrimal duct and dentition, and to correlate those changes.

Results: Chinchilla 1 had a focal soft tissue attenuating expansion of the maxillary bone rostral to the first left premolar interpreted as possible abscessation causing deviation of the nasolacrimal duct over its dorsomedial margin. The right nasolacrimal duct appeared normal. Chinchilla 2 had periapical abscessation of a retained subgingival left maxillary incisor fragment which extended into the nasal cavity causing focal narrowing and distal dilation of the left nasolacrimal duct. Complete contrast infusion of the right nasolacrimal duct could not be completed on Chinchilla 2. A focal area of superficial corneal fibrosis ipsilateral to the obstructed nasolacrimal duct was also identified in Chinchilla 2. Treatment consisted of occlusal adjustments to correct the coronal elongation, systemic antibiotics (metronidazole and either marbofloxacin or azithromycin), and topical tear replacement therapy and diclofenac as needed. Ocular discharge decreased in both chinchillas but did not resolve long-term in either animal.

Conclusions: Chronic dental disease including periapical abscessation in chinchillas can obstruct the nasolacrimal duct, leading to impaired tear drainage. Management of dental disease is crucial to maintain patency of the nasolacrimal duct.