Endoscopic Diagnostics of Chronic Diseases of the Nasal Cavity in Dogs

Knotek Z, T. Fichtel , R. Husník, J . Benák: Endoscopic Diagnostics of Chronic Diseases of the Nasal Cavity in Dogs. Acta Vet. Brno 2000, 69:319-326. Results of a two-year project focused on diagnostic efficacy of various endoscopic techniques and their combination in 52 dogs affected by chronic diseases of the nasal cavity are presented. The rigid endoscope Hopkins (diameter 2.7 mm, length 18 cm, Karl Storz, Tuttlingen) and the flexible endoscope Olympus BF Type PE (Olympus Optical Co., Hamburg) were used for anterior and posterior rhinoscopy, respectively. Bioptic samples of damaged nasal tissues were collected under endoscopic guidance, fixed in 10% buffered neutral formaldehyde for 12 to 24 h and processed by the conventional paraffin technique. Deep swabs for bacteriological and mycological examinations were also collected under rhinoscopic guidance. Bacterial and fungal rhinitis and neoplasms were diagnosed in 50%, 19.2%, and 23.1% of the patients, respectively. Foreign bodies were found in four patients (7.7%). Three patients affected by mycotic rhinitis developed fungal plaques on the nasal mucosa. The passage of endoscope was completely blocked by tumours in the anterior part of the nasal cavity in two patients. Destructive lesions were found mostly in patients with chronic nasal problems (aspergillosis, foreign body, chronic bacterial infection). Anterior rhinoscopy with a rigid endoscope and posterior rhinoscopy with a flexible endoscope yielded correct diagnoses in 55.8% and 26.9% of the patients, respectively. Examination by both the techniques increased this proportion to 82.7%. The reliability of histological examination of tissue samples collected by endoscope-assisted biopsy was 94.4%, while that of the other laboratory test only 41.7%. Rhinoscopy can significantly improve the reliability of diagnosis of canine chronic diseases of the nasal cavity. Rhinoscopy, rhinitis, nasal tumours in dogs Diseases of the nasal cavity in dogs often develop into a complicated chronic process. Predisposed to such diseases are above all dolichocephalic breeds (Retriever, Collie, German Shepherd Dog). Endonasal neoplasms develop slowly, but involve progressively large areas of the nasal cavity and seriously affect the physiology of breathing. The most conspicuous clinical signs of pathological processes affecting the nasal and paranasal cavities include nasal discharge and sneezing. As the disease acquires chronic character, the frequency and intensity of sneezing decrease and nasal discharge becomes the dominant sign. Inflammation develops as an acute health problem, but often acquires chronic character. Chronic rhinitis with relapsing epistaxis can indicate allergic character of the disease (Forbes Lent and Hawkins 1992). The initially clear and unilateral discharge becomes purulent, haemorrhagic, and bilateral. Inspiration becomes laborious, because obstacles in the nasal airways increase air resistance by 50 to 70% of the values considered normal in healthy quiescent dogs (Robinson 1992). Erosions, ulcerations and loss of pigment are apparent on the outer surface of nostrils. Advanced stages are characterised by destruction and distorsion of the nasal cavity. Patients affected by diseases of the nasal cavity, nasopharynx, or paranasal cavities develop nasal discharge, epistaxis, stridor, and facial oedema. The process is bilateral in approximately one half of the patients. ACTA VET. BRNO 2000, 69: 319–326 Address for correspondence: Doc. MVDr. Zdenûk Knotek, CSc. Small Animal Clinic, Faculty of Veterinary Medicine University of Veterinary and Pharmaceutical Sciences Palackého 1-3, 612 42 Brno, Czech Republic Phone: + 420 5 4156 23 82 E-mail: [email protected] http://www.vfu.cz/acta-vet/actavet.htm