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

Abstract

BackgroundIt has not yet been shown that ossification of ungular cartilages (OUC) is a pathological condition. Beside heredity, factors such as sex, age, repeated concussion, local trauma, hoof and body size have been suggested as contributing factors for OUC development. By comparing radiographs of front hooves from cold-blooded trotters with different age we wanted to evaluate when development of OUC in cold-blooded trotters occurs and if and when it stabilizes in relation to age and workload. Diagnosis and grading of OUC were based on radiological field examinations of 649 Swedish and Norwegian cold-blooded trotters’ front hooves. A hundred and forty-seven of the horses were re-examined 3-13 years (mean age 9, median 8 years) after the first occasion. All radiographs were evaluated blind, using two different grading systems for OUC. Work load, in form of number of races completed, and body size score were collected from official data. Four statistical ordinal regression models were used, compared and evaluated.ResultsWe identified a breakpoint at 2.8 ± 0.38 years of age when ossification ends and proposed a simpler grading system with more consistent results. There was no significant correlation between body size and grade of OUC. Comparison of different statistical methods for evaluation of ordinal data revealed a piecewise linear regression model as most suitable.ConclusionsIndividuals with OUC developed this condition during the stage of life when their hooves develop in size. Results from this study can assist equine practitioners when examining and for understanding this condition in their clinical work and is also beneficial for the Scandinavian equine industry when devising breeding programs.

Pathological Changes in Early Medieval Horses from Different Archaeological Sites in Poland

“…In principle, the calcification of these cartilages is not considered to be a pathological change unless it is accompanied by the inflammation of the fixation apparatus of the toe. This phenomenon is thought to occur in all horses after the age of three years, with the rate of calcification being highly dependent on genetic factors [41]. A low ring or osteoarthrosis of the hoof joint was found in one phalanx distalis.…”

“…The methodology of Loch and Melvin [38] was employed to determine the age. The results obtained were discussed based on contemporary knowledge in veterinary medicine [39][40][41] as well as palaeopathology [42,43].…”

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

“…Horses <2-years-old were included since training on hard surfaces normally starts as yearlings in this breed which may affect both development of distal phalanx, OUC and pathological conditions of the front feet. In addition, 147 of the horses were re-examined, mean 9 and median 8 years after the first occasion and are also included in a study of ossification development over time [ 17 ]. For these horses, the grade of OUC at the last examination was the OUC grade used in this study.…”