Equine Odontoclastic Tooth Resorption and Hypercementosis (EOTRH) in Icelandic Horses in Germany: A Correlation Between Clinical and Radiographic Findings

Equine odontoclastic tooth resorption and hypercementosis (EOTRH) is a widespread dental disease with an unknown aetiology, mainly affecting the incisors and canine teeth of senior horses. Being clinically asymptomatic in early stages but progressively destructive and painful in many cases highlights the need for improvements in early diagnosis of EOTRH. This study describes how clinical and radiological findings correlate with distinguishing EOTRH-specific symptoms from non-specific findings. Clinical and radiographic examinations of the rostral oral cavity were performed in 154 Icelandic horses. Each horse received a separate assessment of clinical and radiographic findings and was clinically and radiographically classified as either EOTRH Stage 0 (no findings), Stage 1 (suspicious), Stage 2 (mild), Stage 3 (moderate) or Stage 4 (severe). Analysis revealed statistically significant association between non-age-correlated bite angle, fistulae, gingival swelling, gingival recession as well as gingivitis and radiographic EOTRH diagnoses. Meanwhile, no statistical association was found between the occurrence of calculus or tooth mobility and EOTRH diagnosis. Understanding the interaction of the different symptoms enables further diagnostics (e.g., radiography) to be conducted at an early stage, and therefore EOTRH can be diagnosed and treated at its earliest possible stage.