Summary The survey comprised 443 horses, referred to the clinical department of the Equine Research Station, with a history of a thoracolumbar (TL) complaint. A wide range of lesions were capable of producing back problems and more than one condition or site of injury was found in 75 animals (17 per cent). There were 103 horses (19.7 per cent) with no evidence of damage to the TL spine or its associated structures. In 66 of these cases, clinical signs were attributed to a variety of hindlimb lamenesses and, in 37, no specific diagnosis could be made. Soft tissue injury was diagnosed in 203 cases (38.8 per cent), the most frequent sites being the longissimus dorsi muscles and/or the supraspinous ligament in the caudal withers and cranial lumbar regions. Chronic sacroiliac strain or mild sacroiliac instability was also a frequent cause of low back trouble in competitive horses. Other conditions included tying‐up, subluxation of a lumbar vertebra and neuritis of the cauda equina. Fifteen cases (2.9 per ***cent) of vertebral malformations were found including scoliosis, lordosis and kyphosis. Vertebral lesions accounted for 202 (38.6 per cent) of the diagnoses. The most common condition was associated with crowding and overriding of the dorsal spinous processes in the caudal thoracic and cranial lumbar regions. This was most often diagnosed in competitive jumping horses (173 cases) and caused a loss of suppleness and spinal flexibility resulting in lowered performance and bouts of back pain. There was a comparatively low incidence of fractures (13 cases) and degenerative spondylosis (14 cases). Résumé II s'agit d'une étude portant sur 443 chevaux confiés au département clinique de la Station de Recherche Equine de Newmarket avec des commémoratifs de lésions thoracolombaires (TL). La gamme des lésions pouvant engendrer des troubles dorso‐lombaires est vaste, et 75 animaux, soit 17% furent trouvés porteurs de deux ou de plusieurs lésions distinctes. En revanche, 103 chevaux (19.7%) se révélèrent indemnes de lésions vertébrales ou paravertébrales thoracolombaires. Pour 66 de ces animaux, les signes cliniques furent attribués à diverses sortes de boiteries postérieures. Pour les 37 autres, on ne put produire un diagnostic spécifique. Des lésions des tissus mous furent diagnostiquées dans 203 cas (38.8%), le site le plus fréquent étant le long dorsal, et, ou le ligament sus épineux dans la région postérieure du garrot ou dans la partie antérieure des lombes. Des lésions sacro iliaques chroniques ou une instabilité sacro iliaque modérée furent également considérées comme la cause fréquente de troubles dorso‐lombaires chez les chevaux de compétition. Les autres affections identifiées furent le syndrome tying up (myoglobinurie fruste), la sub‐luxation d'une vertébre lombaire et la névrite de la queue de cheval (cauda equina). Quinze cas de malformations vertébrales furent identifiés (2.9 %) y compris des cas de lordose, scoliose et cyphose. Des lésions vertébrales furent diagnostiquées dans 38.6 % des cas, soit 202 animaux. ...

Summary This paper describes a collaborative project, conducted under the auspices of the British Equine Veterinary Association's survey section and financed by the Horserace Betting Levy Board, with the objective of collecting relevant data from breeding and racing statistics and evaluating losses (areas of wastage) that occur in the Thoroughbred racing industry. The investigation, which was carried out between 1977 and 1980, was divided into 2 parts. In Phase 1 the available statistics showed that considerable wastage existed from the time of covering to the appearance of the progeny on the flat, but that losses were closely consistent each year. Of the active mares in the General Stud Book for the seasons 1973 to 1979, 11.8 per cent were eliminated because no covering return was received and a further 10.1 per cent were either not covered, were covered by halfbreds or foaled abroad. The remaining mares, which were confirmed to have been covered (ie, applicable covered returned mares) were used to base the estimates of wastage. These were failure to conceive, 22.5 per cent, aborted or had a non‐surviving foal, 10.1 per cent, live progeny not named, 13.9 per cent, named animals not trained (2 to 4) years), 20.1 per cent and trained animals that did not run at 2 to 4 years, 6.2 per cent. This gave an overall figure for wastage of 72.8 per cent. Data on the numbers of outings as well as the numbers of animals imported and exported are quoted. An estimate of the cost of these losses was made under the following categories: lost stallion fees, keep of mares, keep of unnamed foals and keep of named animals that did not run. The cumulative losses for the 1974 season and its progeny was calculated to be at least £15.2 million. Phase 2 examined more specifically some of the areas of wastage caused by breeding losses and the reasons for an unsatisfactory number of racing appearances. The most substantial reason for not competing or competing less than the average number of times was horses showing little or no ability to race. In a survey of 762 horses, 26.5 per cent did not race up to the age of 4 years; of these just over one third were being kept as “store” animals for National Hunt racing. The final part of the survey examined the veterinary reasons for wastage. In 314 horses in Newmarket, lameness was the most significant factor. There was an incidence of lameness of 53 per cent at some periods during the season and in 20 per cent of cases the lameness was sufficient to prevent racing afterwards. Résumé Cet article produit les résultats d'une étude menée sous les auspices de la commission d'enquète de la BEVA, étude financée par le British Horserace Betting Levy Board. L'objectif de cette étude était de réunir des informations utilisables à partir des statistiques des courses et de l'elevage afin d'évaluer les pertes et les points faibles de l'industrie des courses de pur sang. Les recherches ont été conduites entre 1977 et 1980. Les résultats sont exposés en deux parties. Dans la première, les statistiques disponib...

Summary This paper reviews current developments in equine osteochondrosis complex and the clinical syndromes associated with it. Although the primary lesion has been defined as a failure of endochondral ossification, its definitive cause is unknown and appears to involve heredity, growth rate, nutrition, mineral imbalance, endocrinological dysfunction and biomechanical trauma. Despite the international importance of osteochondrosis in horses, surprisingly few controlled investigations have been performed on its pathogenesis. The studies that have been conducted suggest that local effects on differentiating growth cartilage are the key to a more complete understanding of the problem. Gaps in the current knowledge include in‐depth understanding of the life cycle of chondrocytes in growth cartilage, the process of mineralisation and the use of a standard experimental model for the induction of osteochondrosis. The ultimate goal of osteochondrosis research must be to prevent or reduce the incidence of the condition in horses.

Summary The existence of an innate insulin insensitivity in ponies was investigated and compared with the situation in larger breeds of horse. Ponies that were fat or had previously suffered laminitis were found to be far more intolerant to oral glucose loading (1 g/kg bodyweight [bwt]) than normal ponies or Standardbreds. These ponies also exhibited a far greater response in plasma insulin levels after glucose loading. Insulin response tests (0.4 iu/kg bwt insulin intravenously) showed only a minimal and very protracted response in both the fat and laminitic groups. The relevance of these findings in regulation of carbohydrate and lipid metabolism, and their role in the pathogenesis of hyperlipaemia, are discussed.