ABSTRACT
Otitis media is common and is almost invariably accompanied by otitis externa1-3. Furthermore, in the vast majority of cases the infection within the middle ear appears to result from extension of otitis externa, rather than from ascending infection via the auditory tube or as a result of haema togenous infection1. However, it may be that the role of the auditory tube in the aetiology of canine otitis media has not been fully appreciated, since its normal physio logical role is critical to middle ear homeostasis, both microbiological and environmental4,5. Most cases of otitis media appear to be missed, since in one study the duration of the condition, before diagnosis, was in excess of 2 years in over onehalf of cases3.
