N05 - Breed Predispositions for Canine Otitis Media with Intracranial Extension

Abstract:

Background: Intracranial extension of otitis media (OM) infection is an infrequent, yet severe complication in dogs. The prevalence and breed predispositions for this complication have yet to be described. Hypothesis: Prevalence of otitis media with intracranial extension (OMIE) is higher in French Bulldogs than other breeds. Animals: 314 client-owned dogs with definitively diagnosed OM from January 1990-August 2024.

Methods: Retrospective study. Medical records were reviewed and cases with a histopathologic and/or microbiological diagnosis of OM were included. Extension of OM was based on histopathology, advanced cross-sectional imaging or cerebrospinal fluid analysis. Fisher’s exact tests were performed to compare each breed with at least 5 cases against the hospital population and OM population. Holm-Sidak correction for multiple comparisons was performed.

Results: OMIE and OM without extension was identified in 43 and 271 dogs respectively. Predisposition for OM was identified in French Bulldogs (OR 12.12 [95% CI: 8.92-16.46]), American Cocker Spaniels (8.59 [6.06-12.17]), Pugs (6.40 [4.07-10.09]), Bulldogs (4.70 [2.84-7.78]), Cavalier King Charles Spaniels (6.07 [3.23-11.43]) (P< 0.0001 each), and Standard Poodles (4.82 [2.56-9.06]; P=0.0005). Only French Bulldogs were predisposed to OMIE both relative to the hospital (51.50 [28.19- 94.10]; P< 0.0001) and OM populations (6.36 [0.08 to 0.32]; P< 0.0001). The most common organism in the OMIE group was Staphylococcus sp. 30-day survival was excellent (35/38; 92%). Conclusions and clinical importance: French Bulldogs are predisposed to the development of OMIE which does not reflect a higher incidence of middle ear disease alone. This may reflect anatomical variations in skull morphology associated with routes of extension.