Palaeopathology and horse domestication: the case of some Iron Age horses horn the Altai Mountains, Siberia

We discuss the use of palaeopathological indicators in horse skeletons as potential sources I of evidence about the use of horses for riding and traction. We suggest that this type of information can provide an important and perhaps more reliable complement to other indicators of domestication such as morphological changes, kill-off patterns and bit wear, which suffer from various ambiguities of interpretation. We emphasise the importance of studying the skeletons of modern control samples of horses of known life histories as a constraint on the interpretation of palaeopathological evidence and demonstrate the viability of the technique through a comparison of free-living Exmoor ponies with Iron Age Scythian horse remains from Siberia. We demonstrate that stresses caused by riding produce characteristic lesions on the vertebrae which can be distinguished from age-related damage in free-living animals, and in addition that these stresses could have been moderated by changes of saddle design in the Medieval period. These results also throw new light on customs associated with horse burial

Osteochondrosis lesions of the lateral trochlear ridge of the distal femur in four ponies

Lesions of the lateral trochlear ridge (LTR) of the distal femur were investigated in four pony or pony cross horses. The animals were all geldings and were six to 15 months of age. Lesions were bilateral in three ponies and unilateral in one. Femoropatellar joint effusion and lameness were present in two ponies; clinical signs were absent in the others. The proximal LTR was affected in all four animals. The radiographic appearance of the lesions was a subchondral defect containing mineralised bodies. Arthroscopic and postmortem examination findings included an osteochondral flap, a fissured or irregular articular surface and a smooth surface overlying focally thickened cartilage that extended into subchondral bone. Thickened articular cartilage was a histological feature of all the lesions. Among the other histological features, the most common were chondronecrosis, chondrocyte clusters, phenotypically abnormal chondrocytes, horizontal fissures at the osteochondral junction and retained blood vessels. The signalment of the four ponies, their clinical signs and the pathological features of their lesions were consistent with osteochondrosis of the LTR in horses. The use of multiple criteria was considered to be important in making a specific diagnosis

Problems and pointers in ostechondrosis: 20 years on.

Twenty years ago a supplement of Equine Veterinary Journal was devoted to equine osteochondrosis (OC) and recognised the importance of this developmental disease to the equine industry. In the accompanying editorial several controversial issues were identified and a number of areas for further research were highlighted. Today, equine OC is still a major clinical problem, but the on-going research has resulted in much improved knowledge and understanding of this highly complicated disease. There is still conflicting evidence on the prevalence of OC due to the dynamic character of the condition, widely varying definitions in the literature, and the range of joints affected. Nevertheless there is now convincing evidence that early vascular damage, leading to chondronecrosis, is the major mechanism of onset. The aetiological factors that determine whether a horse will develop clinical signs of OC remain obscure and the complex nature of OC and its multi-factorial character has been clearly demonstrated by genetic studies. These have shown a multitude of loci on a variety of chromosomes linked to osteochondrotic phenotypes, depending on the type of manifestation of OC, the joint involved and the breed. The controversy surrounding the possible key role of copper in the pathogenesis of OC in the early 1990s has evolved into a more limited contribution to repair thus making it just one of the many environmental factors that may have an effect on the occurrence of OC, but not a decisive one. The semantic debate concerning the most appropriate nomenclature seems to have crystallised into a consensus on terminology at three levels: OC or osteochondritis dissecans (OCD) for the disturbance in the process of endochondral ossification, juvenile ostechondral conditions (JOCC) for all joint and growth plate related disorders, and developmental orthopaedic diseases (DOD) for the full range of skeletal conditions in young horses. Future progress in improved management of OC can be expected from more research on cellular and molecular processes and the influences that determine the process of endochondral ossification, the process of articular cartilage maturation, and from epidemiological studies quantifying the long-term effects of OC on health and performance