Diseases of the nasal cavity in the dog. Aetiology, symptomatology, diagnostics

Abstract

A system of intravital differential diagnostics of diseases of the nasal cavity was verified in 40 dogs. Patients were induced to analgosedation by a combination of medetomidine and butorphanol for the purpose of taking radiographs of the nasal cavity. In order to obtain samples for cytology and histological examination, patients were induced by propofol and then kept under inhalation anaesthesia using halothane or isoflurane. A rigid endoscope (Hopkins, diameter 2.7 mm, 18 cm) was used to examine the nasal cavity thoroughly. Tissue specimens from areas of damaged mucosa and inner structures of the nasal cavity were under endoscopic guidance sampled using bioptic forceps. One part of samples was used to make impression smears for cytological evaluation; the other part for histological processing. In patients suffering from chronic infectious rhinitis and neoplasia we found in both groups marked and advanced changes in the internal architecture of the nasal cavity (aggressive lesions). In several cases of mycotic rhinitis caused by fungi of the Aspergillus genus we observed typical pale plaques. Foreign bodies, mainly such as awns and parts of grass spikes, were mechanically removed using endoscopic forceps. Granulomas had a tendency to profuse bleeding. There were no serious cases of severe bleeding during examination. Results of bacteriological cultivation were compared to those obtained by cytology and histology. In 40 of these combined examinations there were in 16 cases (40%) confirmed bacterial rhinitis cases without the presence of fungi and changes typical of neoplastic processes. Staphylococcus intermedius, Streptococcus canis and Pasteurella canis were cultured most frequently. Other bacterial agents were diagnosed only exceptionally. Mycotic infections were found in 7 cases of chronic rhinitis (i.e., 17.5%). The genus Aspergillus amounted to more than 85% of mycotic agent detection. Fungi occurred as a complication to a foreign body in the nasal cavity in two cases. There were no cases of allergic rhinitis in the group of patients studied. Malignant neoplasia were prevailing (77.8%). Osteosarcoma, lymphosarcoma and adenocarcinoma were frequent neoplasia found in the nasal cavity of the dog.