Chronic nasal discharge is a common clinical complaint in dogs. Lymphoplasmacytic rhinitis (LPR) is particularly frustrating since little is known about the clinical characteristics of the disorder. In this study, medical records were searched for a histologic diagnosis of LPR and 55 cases were identified. In 15 dogs, primary intranasal pathology was found but in the remaining 40 dogs, no specific cause for inflammatory nasal histology was identified. Large breed dogs were most commonly represented in this group (31/40) with German shepherds (n=6) and collies (n=2) appearing more than once. Treatment prior to presentation included antibiotics (91%), antihistamines (29%), and glucocorticoids (26%). Rhinoscopy (n=39) commonly demonstrated increased mucous and epithelial inflammation, and turbinate destruction was noted in 20% of the dogs. Microbial cultures and fungal growth were minimal or absent with no Aspergillus spp. present. Inflammation was mild (28%), moderate (49%), or severe (23%). Six dogs had unilateral LPR. Purely lymphoplasmacytic infiltration was noted in 13 of 40 dogs and 58% also had neutrophils in the histologic description. Further investigation into the etiology of LPR is needed to establish the underlying cause and to determine effective treatment protocols for affected dogs.

COMMENTARY: Of the many causes of nasal discharge in dogs, lymphoplasmacytic rhinitis is the most enigmatic since so little is known about it. Treatment can really only be effectively prescribed when the cause is known. This retrospective study of 40 such cases sheds some light on the subject and could pave the way for future study and a better understanding of the disease.

Lymphoplasmacytic rhinitis in 40 dogs: 1997-2002. Windsor RC, Johnson LR, Herrgeseli EJ, DeCock H. ACVIM Proceeedings, Abstract 204, 2003, p 996.