Significance of ossificated ungular cartilages regarding the performance of cold-blooded trotters

Abstract

BackgroundOssification of the ungular cartilages (OUC) in the foot of horses has been studied for more than 100 years. There is a high heritability of this condition but its clinical relevance has remained questionable. Nevertheless, modern equine orthopedic literature ranks OUC as one of top 10 causes of lameness in cold-blooded trotters and stallions of these breeds are excluded from breeding if they have more than mild levels of side bones. Cold-blooded trotters have been used for racing for many decades and official sports data have been available since 1923. A decreased performance is often the only obvious clinical sign noticed by trainers and owners motivating them to seek professional help from veterinarians and farriers. By comparing various performance parameters in Swedish-Norwegian cold-blooded trotters without and with different grades of OUC, we aimed to determine the clinical relevance of ossified hoof cartilages in a population of high-performance horses.Front hooves from 649 Swedish-Norwegian cold-blooded trotters were evaluated radiologically regarding OUC. Breeding index and official sports data originating from strict protocols kept by groups of officials in trotting associations was used for comparison of performance of these horses that together had competed in more than 23,000 races between 1973 and 2009. Generalized linear mixed models were used for the statistical analyses. The response variable was modeled using ordinal logistic models with a multinomial distribution and a cumulative logit link function. The horse was used as a random factor.ResultsSignificant effects of gender on performance were demonstrated, but no correlations were found between different positions nor grades of ossified ungular cartilage and number of starts, running pace, race winnings, number of races completed in a regular gait.ConclusionsOssification of the ungular cartilages does not cause decreased performance in cold-blooded trotters and is therefore most likely not a cause of clinical or subclinical lameness in this breed. Results from this study can assist equine professionals in evaluating and interpreting the clinical relevance of radiological findings on ossified hoof cartilage among heavy and high-performing horses.

Ossification of ungular cartilages in front feet of cold-blooded trotters - a clinical radiographic evaluation of development over time

“…ossification. Besides the obvious need to standardize the radiological examination technique, we believe that using our more forgiving new scale approach is beneficial in clinical practice, especially since our recent studies [ 27 ] indicated that OUC had no effect on performance in cold-blooded trotters and since field radiography, unfortunately, often is performed under non optimized circumstances.…”

“…Clinical experience shows that radiological examination technique and artifacts such as small amounts of mud on hooves might both affect the number of separate centers of ossification found in a population. However, the fact that we had this problem on two radiographs did not alter the result that presence of separate centers of ossification does not affect the performance of the horse [ 27 ].…”

Analysis of the prevalence of osteoarticular pathologies in horses based on the results of radiography

“…Проблематику окостеніння суглобових хрящів вивчають вже більше 100 років та доведено, що це явище може мати спадковий прояв або бути наслідком травмування. Дані стосовно кореляції ступеня осифікації у межах суглоба та зниженням продуктивності тварини відсутні [30,31]. Проте наявність осифікації у скакальному суглобі в більшості випадків стає причиною остеоартриту цього суглоба [32].…”