Calcium carbonate rhinolithiasis associated with chronic lymphocytic rhinitis in a pet rabbit (Oryctolagus cuniculus).

A 6-year-old intact female domestic dwarf rabbit (Oryctolagus cuniculus) was referred because of a chronic obstructive rhinitis not resolving despite antibiotic treatments. Computed tomography examination revealed 2 sub-obstructive structures of mineral density in the right nasal cavity and nasopharynx. Neoplasia and rhinolithiasis were the main differential diagnoses. A dorsal rhinostomy was performed and 1 mineralized lesion was removed. Infrared spectrophotometric and histological examinations of the lesion and nasal mucosa were consistent with a 100% calcium carbonate rhinolith with bacterial colonization and chronic lymphocytic rhinitis. Clinical signs improved during the first 4 wk following surgery. However, despite inhaled anti-inflammatory treatment, the rabbit's condition deteriorated when the rhinostomy site closed, and she died 7 wk after surgery. Rhinolith and lymphocytic rhinitis should be considered as differential diagnoses for upper respiratory tract signs in rabbits resistant to antimicrobial treatment. Key clinical message: Rhinolithiasis and chronic lymphocytic rhinitis should be included in the differential diagnoses of rabbits presenting with chronic obstructive upper respiratory tract signs characterized by purulent nasal discharge and failure of treatment despite adequate antimicrobial therapy, especially with unilateral signs. Computed tomography and rhinoscopy with biopsies are suggested to explore those possibilities.