Factors associated with equine aural plaque in Brazil.

Background - Aural plaques can be found on the inner surfaces of one or both ears of horses. Despite their low malignancy, these lesions can sometimes cause discomfort and sensitivity in horses, and a loss in commercial value due to their aesthetic effect. There has been a study describing the epidemiological features and the clinical prevalence of equine aural plaques in Brazil. Hypothesis/Objectives - To determine the clinical prevalence and selected associated factors of aural plaques. Animals - In the study, 891 horses were assessed for aural plaques. The sample group had a median age of 5 years and comprised both sexes and various breeds from different regions of Brazil. Methods - Horses were evaluated by a general observation of the body and a detailed observation of both ears. Data on the management system, characteristics of the lesions, the presence of ticks and ear grooming were collected for 109 clinically affected horses. An assessment of the frequency distribution of the disease and its characteristics was performed. Association tests were conducted to establish the relationships between the variables studied. Results - In 85% (40 of 47) of farms assessed, at least one horse presented with aural plaques. In 14.8% (132 of 891) of the horses, lesions characteristic of aural plaque were detected. Significant associations between the prevalence of "coalescing" lesions and a "semi-intensive" management system and ear grooming were detected. Conclusions - The findings confirm the extensive distribution of this disease in Brazil and its association with several management factors.