For improvements to the safety and welfare of racehorses to be possible, it is essential to have access to basic descriptive information about the veterinary incidents encountered during horseracing. A 3 year surveillance study (1996-1998) was conducted by The Jockey Club into racing injuries, other postrace clinical problems and fatalities from all 59 British racecourses (mainland Britain only) to identify risk factors. During the survey there were 222,993 racing starts: 106,897 starts in flat races on turf (47.9%), 26,519 starts in flat races on all-weather surfaces (11.9%), 30,932 starts in chases on turf (13.9%), 51,786 starts in hurdle races on turf (23.2%) and 6,859 starts in National Hunt flat races (3.1%). Information was recorded about age of horses, racing surfaces and clinical events observed or attended by a veterinary team of 2 clinicians and one veterinary surgeon employed by the racing authority. Of the 2358 clinical events reported (1.05% of all starts), 1937 involved the musculoskeletal system and 421 involved other body systems. Six hundred and fifty-seven incidents (0.29% of starts) resulted in death or euthanasia. Eighty-one percent of limb injury reports involved forelimbs and 46% involved flexor tendons/suspensory ligaments. Nonlimb problems included epistaxis (0.83/1000 starts), 'exhausted horse syndrome' (0.47/1000 starts) and paroxysmal atrial fibrillation (0.20/1000 starts). Incidents including fatalities per 1000 starts were 24.7 from chases, 19.45 from hurdle races, 8.46 from National Hunt flat races and 3.97 from flat races. The overall tendon injury was higher in chases than in hurdle races, even though age-specific rates of tendon injury were higher in hurdle races than in chases. The risk of injuries per start increased significantly with age, while softer racing surfaces were associated with fewer fatalities and injuries than firmer surfaces. The survey described in this paper has provided an up-to-date description of the fatal and non-fatal horseracing incidents under conditions on mainland Britain, enabling progress to be made towards improving the safety and welfare of racehorses.

Racehorse injuries, clinical problems and fatalities recorded on British racecourses from flat racing and National Hunt racing during 1996, 1997 and 1998

The findings of a retrospective survey of 1393 Thoroughbred mares visiting 22 studfarms in the Newmarket region of the UK during the 1998 mating season were compared with those of a similar study undertaken in 1983. The effects of mare age and status, stallion, month of mating, application of uterine treatments and other parameters on the rates of singleton and twin conception and subsequent pregnancy losses were analysed. Mare age and status significantly affected the per cycle pregnancy rate and the incidence of pregnancy loss. Overall, the mean number of matings per oestrus was 1.12 and the mean number of times a mare was mated until diagnosed pregnant at 15 days after ovulation was 1.88. An overall mean per cycle pregnancy rate of 59.9% at 15 days after ovulation resulted in 94.8% of the mated mares being pregnant at least once at 15 days after ovulation. This high initial pregnancy rate fell to 89.7% by Day 35 and 87.5% by the time of the October pregnancy test; 82.7% of the mares surveyed gave birth to a live foal at term, which compares favourably with the proportion of mares foaling in 1983 (77%). However, despite improvements in the foaling rates over the last 15 years, the overall rate of pregnancy failure remains high and represents a major loss to the Thoroughbred breeding industry.

Reproductive efficiency of intensively managed Thoroughbred mares in Newmarket

The medical treatment of osteoarthritis (OA) in the horse is one of the most utilized therapeutic regimens in the equine practice. It is important to understand the anatomy of synovial joints and the pathophysiology of the disease process to treat OA adequately. Once a thorough understanding of the disease process is comprehended the proper combination of systemic nonsteroidal anti-inflammatory drugs (NSAIDs), intraarticular steroids, viscosupplementation and chondroprotectants can be used to treat the disease and inhibit further progression of degenerative changes to the cartilage surface. The equine practitioner is faced with many choices for controlling inflammation in OA. This review presents the background and appropriate uses of various NSAIDs such as phenylbutazone, flunixin meglumine, ketoprofen, naproxen, and carprofen as well as their associated toxicities. Various steroid formulations exist for intraarticular (IA) administration and much has been learned in the past decade regarding correct dosage, frequency of administrations, indications and toxicity. This review presents IA steroids and their indications in addition to various chondroprotective drugs that also exist to control inflammation and provide viscosupplementation. Data are also given on disease modifying OA drugs such as glucosamine and chondroitin sulphate that have more recently become available to the equine practitioner.

Medical treatment of osteoarthritis in the horse - a review.

Background: There are no published studies on stem cells from equine cord blood although commercial storage of equine cord blood for future autologous stem cell transplantations is available. Mesenchymal stem cells (MSC) have been isolated from fresh umbilical cord blood of humans collected non-invasively at the time of birth and from sheep cord blood collected invasively by a surgical intrauterine approach. Mesenchymal stem cells isolation percentage from frozenthawed human cord blood is low and the future isolation percentage of MSCs from cryopreserved equine cord blood is therefore expectedly low. The hypothesis of this study was that equine MSCs could be isolated from fresh whole equine cord blood. Results: Cord blood was collected from 7 foals immediately after foaling. The mononuclear cell fraction was isolated by Ficoll density centrifugation and cultured in a DMEM low glucose based media at 38.5°C in humidified atmosphere containing 5% CO2. In 4 out of 7 samples colonies with MSC morphology were observed. Cellular morphology varied between monolayers of elongated spindle-shaped cells to layered cell clusters of cuboidal cells with shorter cytoplasmic extensions. Positive Alizarin Red and von Kossa staining as well as significant calcium deposition and alkaline phosphatase activity confirmed osteogenesis. Histology and positive Safranin O staining of matrix glycosaminoglycans illustrated chondrogenesis. Oil Red O staining of lipid droplets confirmed adipogenesis. Conclusion: We here report, for the first time, the isolation of mesenchymal-like stem cells from fresh equine cord blood and their differentiation into osteocytes, chondrocytes and adipocytes. This novel isolation of equine cord blood MSCs and their preliminary in vitro differentiation positions the horse as the ideal pre-clinical animal model for proof-of-principle studies of cord blood derived MSCs.

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Isolation of mesenchymal stem cells from equine umbilical cord blood

Summary

Necropsies were performed on 496 horses that had a fatal injury or illness at a California racetrack during the period February 20th 1990 to March 1st 1992. The primary cause of death was categorised by breed, activity at time of injury or illness and organ system affected. Most of the submissions were Thoroughbred horses (432) and Quarter Horses (46). Most of the injuries occurred while racing (42%) and in training sessions (39%); with fewer non-exercise (12%) and accident (7%) related injuries or illnesses. Musculoskeletal injuries accounted for 83% of the Thoroughbred and 80% of the Quarter Horse submissions. The Thoroughbred horses incurred 306 fractures with 263 in the limbs and 90% of those in the forelimbs. The proximal sesamoid bone(s), third metacarpal bone and humerus were the most common bones fractured in Thoroughbred horses and Quarter Horses. Other major causes of death included respiratory, digestive and multi-organ system disorders.

Causes of death in racehorses over a 2 year period.

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.



Resume

Cet article produit les resultats d'une etude menee sous les auspices de la commission d'enquete de la BEVA, etude financee par le British Horserace Betting Levy Board. L'objectif de cette etude etait de reunir des informations utilisables a partir des statistiques des courses et de l'elevage afin d'evaluer les pertes et les points faibles de l'industrie des courses de pur sang.



Les recherches ont ete conduites entre 1977 et 1980. Les resultats sont exposes en deux parties. Dans la premiere, les statistiques disponibles ont montre qu'un deficit considerable se produit entre la periode de monte et l'apparition de la production sur l'hippodrome; les pertes sont du meme ordre chaque annee.



11.8% des poulinieres repertoriees au General Stud Book ont eteecartees de l‘etude parce qu'aucun renseignement sur la monte n'a ete renvoye. En outre 10% des poulinieres furent ou bien non saillies ou bien saillies par des demi sang, d'autres mettant bas a l’etranger. On a donc retenu pour servir de base a l'estimation le reliquat, c'est-a-dire celles des poulinieres dont les resultats de saillie furent officiellement confirmes (renseignements effectivement “retournes”).



Les resultats furent les suivants:



— vides (n'ayant pas concu): 22.5%



— avortees ou ayant eu un produit qui n'a pas vecu: 10%



— production vivante non nommee: 13.9% (anonymes)



— animaux nommes qui n'ont pas etea l'entrainement entre deux et quatre ans: 20.1%



— animaux entraines qui n'ont pas couru entre 2 et 4 ans: 6.2%



Au total le deficit s'eleve a 72.8% Les donnees se rapportant au nombre d'animaux importes et exportes sont fournies.



Une estimation du montant des pertes ainsi constatees a ete faite sous les rubriques suivantes: pertes sur les couts de saillie — pertes sur l'entretien des juments — pertes sur l'entretien des poulains anonymes — pertes sur l'entretien des chevaux qui n'ont pas couru.



Cumulees, les pertes pour la saison 1974 et pour ceux des animaux nes cette annee lâ ont ete estimes a plus de 15.2 millions de livres sterling.



Dans la seconde partie, on examine plus particulierement quelques unes des sources de deficit et les raisons du nombre insuffisant des sorties en course. La raison la plus importante pour ne pas courir ou pour courir moins souvent que la moyen ne est l'inaptitude pure et simple a la competition. Pour 762 chevaux on constate que 26.5% d'entre eux n'ont pu courir avant l‘âge de 4 ans. Parmi ceux-ci un peu plus d'un tiers fut conserve pour les programmes de courses a obstacles. La derniere partie de cette enquete etudie les raisons “veterinaires” du deficit. A Newmarket, pour 314 chevaux on a trouve que la boiterie etait le facteur le plus important. A un certain moment, on a constate 53% de boiteries durant la saison et dans 20% des cas les boiteries ont empeche le retour a la competition.



Zusammenfassung

Dieser Beitrag beschreibt eine gemeinsame Untersuchung, die von der BEVA uberwacht und vom Horserace Betting Levy Board finanziert worden ist. Es wurde die Absicht verfolgt, relevante Angaben aus Zucht- und Rennstatistiken zu sammeln und die Verluste, die im Vollblut-Rennbetrieb sich einstellen, auszuwerten. Die Untersuchung erstreckte sich uber die Jahre 1977 bis 1980 und wurde in zwei Teilen vorgenommen. Die zuganglichen Statistiken zeigten, dass in Phase 1 ein erheblicher Verschleiss sich bemerkbar macht zwischen der Deckzeit und dem Erscheinen des Nachwuchses in Flachrennen. Diese Verluste veranderten sich von Jahr zu Jahr kaum. Von den “aktiven” Stuten im General Stud Book wurden zwischen 1973 und 1979 11.8 Prozent eliminiert, weil das Deckergebnis nicht gemeldet wurde und weitere 10.1% wurden entweder nicht belegt oder durch Warmbluthengste gedeckt, oder sie fohlten ins Ausland ab. Die verbleibenden Stuten (Stuten mit bekannten Deckangaben und Abfohler-gebnissen) dienten zu einer Verschleissschatzung:



Keine Konzeption 22.5%



Abort oder nichtuberlebendes Fohlen 10.1%



lebendes, namenloses Fohlen 13.9%



Tiere mit Namen, aber nicht im Training zwischen 2 bis 4 Jahren 20.1%



Im Training, aber nicht im Rennen zwischen 2 bis 4 Jahren 6.2%



Das ergibt eine Verschleissrate von 72.8%. Es werden auch Angaben gemacht uber die Anzahl der bestrittenen Rennen und uber die Zahl importierter, beziehungsweise exportierter Pferde.



Eine Schatzung der durch diesen Verschleiss verursachten Kosten wurde in den folgenden Kategorien angestellt: verlorene Sprunggelder; Kosten der Stutenhaltung; Kosten der Haltung namenloser Fohlen; Haltungskosten fur nicht in Rennen eingesetzte Pferde. Die kumulierten Verluste fur die Decksaison 1974 und fur die Produktion aus dieser Saison wurden auf mindestens 15.2 Mio Pfund geschatzt.



In Phase 2 der Untersuchung wurden bestimmte Aspekte dieser Zuchtverluste spezifischer ausgewertet und die Grunde fur die unbefriedigende Anzahl bestrittener Rennen erforscht. Der wichtigste Grund dafur, dass viele Pferde uberhaupt nie auf die Rennbahn kommen oder nur an einer unterdurch-schnittlichen Anzahl von Rennen teilnehmen, besteht in einer fehlenden oder ungenugenden Eignung als Rennpferd. Von 762 Pferden bestritten 26.5% bis zu einem Alter von 4 Jahren uberhaupt keine Rennen; davon wurde nur etwas mehr als ein Drittel fur den Einsatz in Hindernisrennen “aufgespart”.



Im letzten Teil der Untersuchung wurden die tierarztlichen Grunde fur die Verluste unter die Lupe genommen. Bei 314 Pferden in Newmarket wurde Lahmheit als weit wichtigster Grund festgestellt. Wahrend der Rennsaison ergaben sich Perioden mit einer Lahmheitsfrequenz von 53%, wobei 20% der lahmen Pferde auch spater nicht mehr in Rennen eingesetzt werden konnten.

P. F. Towers-Clark

Papers

An assessment of wastage in thoroughbred racing from conception to 4 years of age