Post mortem survey of equine dental disorders

Abstract

Dental care is an integral part of equine veterinary practice and increased focus has been put on the implications of dental disorders on equine welfare. In South Africa limited reports on dental disorders in the equine population are available, therefore the prevalence of dental disorders in horses in this region is unknown. Additionally, no study has reported on the difference between performing an oral examination on an intact head and a bisected head for the diagnosis of dental disorders. The objectives of this study were to describe the prevalence of dental disorders in different age groups of an abattoir population of horses, and to compare oral examination of intact and bisected heads. A cross-sectional prevalence study was performed on heads of horses consigned for routine slaughter at Randfontein abattoir in South Africa. Individual horse gender and body condition score were recorded. Age was estimated from dental evaluation. Oral examinations were performed on intact heads with a Haussmann gag head light, mirror, and dental probe by two observers blinded to the findings of each other. Heads were then bisected and examined by the observers individually and in consensus. Age and all lesions were recorded for each horse on a standardised dental chart. Heads from 40 horses were examined between March and November 2012, 19 males and 21 females, divided into immature (2-5 years), adults (6-14 years) and older horses (≥ 15 years). Older horses had a significantly higher prevalence of diastemata (66.7%), focal overgrowths (58.3%), fractures (58.3%) and caries (91.7%), whereas occlusal abnormalities affected all age groups. Disorders associated with deciduous premolars were periodontal pockets (84.6%), wave mouth appearance (53.8%), and diastemata (38.5%). Rostral and caudal overgrowths, periodontal pockets, and fractures were most likely to be diagnosed during the regular oral examination. No significant association was found between body condition score and severe dental disorders. Gasterophilus larvae were detected in the oral cavity of all age groups examined. The prevalence of dental disorders detected was similar or higher than previous studies undertaken outside South Africa, most likely because the oral examination was also performed on bisected heads. The oral examination performed on intact heads was adequate for diagnosing gross dental lesions and disorders, compared to examination of bisected heads, but further diagnostic examination is needed for reliably diagnosing more subtle lesions and disorders. The clinical relevance of G. pecorum detected is of interest.