Silent but Severe: EOTRH Affects Two-Thirds of Aged Icelandic Horses

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

Melusine Tretow, Anna M. Hain, Astrid Bienert-Zeit

Background:
Equine odontoclastic tooth resorption and hypercementosis (EOTRH) is a progressive and painful dental disease primarily affecting incisor and canine teeth in older horses. While EOTRH is commonly underdiagnosed in early stages, its prevalence in Icelandic horses has not been systematically assessed. This study aimed to investigate the clinical and radiographic presentation of EOTRH in Icelandic horses in Germany, with the goal of identifying specific clinical findings that reliably predict radiographic disease.

Methods:
A cross-sectional study was conducted on 154 Icelandic horses aged 15 years or older. Standardized clinical examinations of the rostral oral cavity were performed under sedation, and intraoral radiographs were obtained. Both clinical and radiographic findings were scored and staged on a 0–4 scale. Statistical analysis assessed the correlation between clinical signs and radiographic EOTRH diagnosis, using logistic regression and Cramer’s V for association strength.

Results:
Radiographic signs of EOTRH were detected in 72.2% of horses, while 67.5% were clinically affected. A strong correlation was observed between higher clinical scores and advanced radiographic stages (Pearson’s r = 0.74, P < .001). Clinical findings significantly associated with EOTRH included non-age-correlated bite angle, gingival swelling, gingival recession, fistulae, and gingivitis. Calculus and tooth mobility were not predictive of radiographic disease. Horses with abnormal bite angles had significantly higher odds of EOTRH (OR = 0.051), as did those with gingival swelling (OR = 0.052), gingival recession (OR = 0.14), or gingivitis (OR = 0.30).

Limitations:
Radiographs were obtained under field conditions, sometimes limiting image quality. Subjective assessment of clinical parameters (e.g., bite angle) without precise measurement may introduce variability. Owner-reported dental histories and selection bias toward presumed healthy horses who were later diagnosed with EOTRH may have influenced prevalence estimates.

Conclusions:
EOTRH is highly prevalent and likely underdiagnosed in aged Icelandic horses in Germany. A defined symptom complex—including non-age-correlated bite angle, gingival recession, and bulbous gingival enlargement—strongly predicts radiographic evidence of disease and should prompt further diagnostic imaging. Clinical findings alone cannot rule out EOTRH, reinforcing the importance of routine radiography in older horses for early detection and treatment planning.

Disclaimer: The summary generated in this email was created by an AI large language model. Therefore errors may occur. Reading the article is the best way to understand the scholarly work. The figure presented here remains the property of the publisher or author and subject to the applicable copyright agreement. It is reproduced here as an educational work. If you have any questions or concerns about the work presented here, reply to this email.