The incidence and microbiology of otitis externa of dogs and cats in New Zealand

Authors: Baxter M, Lawler DC
Publication: New Zealand Veterinary Journal, Volume 20, Issue 3, pp 29-32, Mar 1972
Publisher: Taylor and Francis

Animal type: Cat, Companion animal, Dog
Subject Terms: Bacterial, Ear/nose/throat, Fungal/yeast, Inflammation, Disease/defect, Infectious disease, Respiratory system
Article class: Scientific Article

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Abstract: Otitis externa, manifested by inflammation of the external auditory canal and associated excessive secretion of ear wax or discharge, is considered by many to be one of the most common problems encountered in small-animal practice in New Zealand. The condition is usually assessed on the amount, colour and sometimes consistency of the wax or discharge but in some cases can be diagnosed on the erythematous, oedematous or ulcerated appearance of the meatal epithelium. These clinical symptoms may be produced by a complex of factors, ranging from the purely mechanical to the purely infectious. Microbiologically, the majority of cases investigated overseas (reviewed by Grono and Frost, 1969), show a tendency towards the predominant establishment in the affected ear of one or two particular species. Staphylococci, streptococci and various Gram-positive bacilli are usually found in both normal and affected ears, but species of Pseudomonas and Proteus seem to thrive most in the diseased ear. It is these two genera which seem to have the most significance as organisms involved in otitis externa (Fraser, 1961b). It has also been suggested that the yeast Pityrosporum pachydermatis, an organism frequently known as P. canis may play a role in the aetiology of the disease (Gustafson, 1955; Smith. 1968). Otitis externa in dogs has merited world-wide attention but little has been reported on the microbiology of the disease in cats. There has also been no recorded account of the incidence of otitis externa in either species in New Zealand. This paper reports on the incidence and microbiology of the disease in both dogs and cats seen in the Small Animal Clinic at Massey University Veterinary Faculty.

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