Idiopathic lymphoplasmacytic rhinitis (LPR) is recognised frequently in dogs with clinical signs typical of other chronic nasal diseases. The purpose of this study was to determine clinical signs, survey radiographic, rhinoscopic and histologic abnormalities and the response to therapy in dogs with LPR. It was a retrospective study of 33 client-owned animals of various breeds and ages that had been diagnosed with LPR. During the study period, a total of 110 dogs were diagnosed with nasal disease, of which 33 (30%) were diagnosed with idiopathic LPR. The median age was 9 years (range 2.3-17 years) and there were 15 female and 18 male dogs. The majority of dogs showed a mucoid nasal discharge, bilateral stertor and no overt radiographic changes. The most common finding on rhinos copy was hyperaemic nasal mucous membranes with mucoid material accumulation within the nasal cavity. In all 33 dogs bacterial culture yielded no pathogenic bacteria and fungal culture was negative. Histologically, all 33 dogs showed lymphoplasmacytic infiltration within the nasal mucosa. All 33 dogs were treated with systemic and topical corticosteroids for varying lengths of time and dosing intervals. Eleven dogs were treated with concurrent cyclosporine and three dogs underwent allergy testing followed by desensitisation therapy. The best response was seen in the dogs that underwent desensitisation therapy, followed by those treated with corticosteroids and cyclosporine.