Secondary secretory otitis media (SSOM) in 3 cats and 2 dogs.

Objective: To describe secondary secretory otitis media (SSOM) due to obstruction of the nasopharyngeal opening of the auditory tube in cats and dogs and to characterize the effusion by macroscopic description, microscopic cytology and bacteriological analysis.

Material and methods: Three cats and 2 dogs with middle ear effusion and obstruction of the nasopharyngeal opening of the auditory tube detected on CT scans received myringotomy followed by macroscopic description, microscopic cytology and bacteriological analysis of the fluid obtained.

Results: All animals had serous to mucoid middle ear effusions and, in 2 cases, large numbers of inflammatory cells and secondary infection. Causes of auditory tube dysfunction ranged from iatrogenic stents (2) to neoplasia (3). In the non-neoplastic cases, effusion resolved in all cases after removal of the underlying cause.

Conclusions and clinical relevance: Obstruction of the nasopharyngeal opening of the auditory tube leads to accumulation of fluid within the middle ear in cats and dogs. If the cause of obstruction can be removed, fluid accumulation resolves. Fluid characteristics are comparable to middle ear effusions in pugs and French bulldogs. It is important to always examine the nasopharynx in cases of middle ear effusion to rule out SSOM.