Prevalence of peripheral dental caries and diastemata in horses fed high‐carbohydrate diets

Summary Background Peripheral dental caries and diastemata impair equine oral health. Diets rich in soluble carbohydrates are suspected risk factors, but few studies have assessed their impact. In Brazil, sugarcane is widely used as a forage source due to its availability and low cost. Objectives To determine the prevalence and severity of peripheral dental caries and diastemata in horses fed sugarcane compared to horses fed Bermuda grass hay and to investigate their association. Study design Cross‐sectional comparative study. Methods Twenty adult mixed‐breed horses with no history of dental treatment were allocated into two groups based on dietary history: high soluble carbohydrate group (sugarcane, n = 10) and low soluble carbohydrate group (Bermuda grass hay, n = 10). Horses were sedated and underwent complete oral examination using an oral speculum, dental mirror and endoscope. Peripheral caries was classified according to the modified Honma scale, and diastemata were categorised as open or valved. Statistical analyses included Mann–Whitney U test, prevalence difference and Pearson's correlation. Results Peripheral caries affected 37.1% of teeth in the sugarcane group versus 7.9% in the Bermuda grass group. Lesions were more severe in the sugarcane group (grades 1–4) compared to only grade 1 in Bermuda grass group. Diastemata were detected in 80% of horses in the sugarcane group and 50% in the Bermuda grass group, with a higher prevalence in mandibular arcades. Horses fed sugarcane had a 29% higher risk of caries. Caries and diastemata were positively correlated. Main limitations The relatively small sample size restricts the generalisation of the findings and limited the application of more advanced statistical analyses such as regression analysis. Conclusions Sugarcane‐based diets were associated with increased prevalence and severity of peripheral dental caries and diastemata in this sample, underscoring the importance of diet composition in equine oral health and informing preventive management.