Idiopathic lymphoplasmacytic rhinitis in dogs: 37 cases (1997-2002)

OBJECTIVE: To determine clinical signs and rhinoscopic, computed tomographic, and histologic abnormalities in dogs with idiopathic lymphoplasmacytic rhinitis. DESIGN: Retrospective case series. ANIMALS: 37 dogs. PROCEDURE: Clinical information was obtained from medical records. Nasal computed tomographic images and histologic slides of biopsy specimens were reviewed. RESULTS: Dogs ranged from 1.5 to 14 years old (mean, 8 years); most (28) were large-breed dogs. Nasal discharge was unilateral in 11 of 26 (42%) dogs and bilateral in 15 of 26 (58%) dogs. In dogs with unilateral disease, duration of clinical signs ranged from 1.5 to 36 months (mean, 8.25 months; median, 2 months), and in dogs with bilateral disease, duration of signs ranged from 1.25 to 30 months (mean, 6.5 months; median, 4 months). Computed tomography (n = 33) most often revealed fluid accumulation (27/33 82%]), turbinate destruction (23/33 70%]), and frontal sinus opacification (14/33 42%]). Rhinoscopy (n = 37) commonly demonstrated increased mucus and epithelial inflammation; turbinate destruction was detected in 8 of 37 (22%) dogs. Bilateral biopsy specimens from all 37 dogs were examined. Four dogs had only unilateral inflammatory changes. The remaining 33 dogs had bilateral lesions; in 20, lesions were more severe on 1 side than the other. CONCLUSIONS AND CLINICAL RELEVANCE: Findings suggest that idiopathic lymphoplasmacytic rhinitis is a key contributor to chronic nasal disease in dogs and may be more common than previously believed. In addition, findings suggest that idiopathic lymphoplasmacytic rhinitis is most often a bilateral disease, even among dogs with unilateral nasal discharge.