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1.
A retrospective survey was carried out at a Florida racetrack in 1984, to determine the prevalence of exercise-induced pulmonary hemorrhage (EIPH) in Appaloosa horses. Of 94 horses examined endoscopically between 30 and 90 minutes after racing, forty-nine (52%) were found to exhibit some degree of EIPH. There was a significantly increased prevalence of EIPH with increasing age in this population. An increased prevalence of EIPH was noted with mares and geldings as compared with stallions, but this was not statistically significant. More horses bled from the right lung than from the left, but the difference was statistically insignificant. An increased prevalence of EIPH with distance run was evident, but this was not significant when animals of the same age were examined.  相似文献   

2.
Serological analysis of blood samples submitted to the Animal Health Trust showed that during 1995, 185 of 9203 unvaccinated horses (2.0 per cent) tested positive for antibodies to equine arteritis virus (EAV), and that during 1996, 46 of 8851 unvaccinated horses (0.52 per cent) tested positive. During both years thoroughbreds were the predominant breed tested and only a small proportion of these (<0.3 per cent), consisting predominantly of imported mares, were seropositive. In contrast, among standardbred horses, from which samples were actively solicited in 1995, 84 of 454 (18.5 per cent) were seropositive. Among standardbreds there was a difference in prevalence between types of horses, with 3.7 per cent of racing horses, 25 per cent of non-racing horses and 41 per cent of stallions testing seropositive. Investigations of seropositive stallions identified during 1994 and 1995 demonstrated that clinically inapparent equine viral arteritis (EVA) had occurred previously in the UK. Of 50 seropositive stallions, nearly half were standardbreds and nearly all had been imported from either North America or the European Union. Whether 34 seropositive stallions were shedding virus in their semen was established either by test mating, by the serology of the covered mares, or by investigation by MAFF following the introduction of the Equine Viral Arteritis Order 1995. Nine of the stallions (26.5 per cent) were identified as presumptive shedders of EAV in semen and among specific breeds, viral shedding was identified in six of 15 (40 per cent) standardbreds and three of nine (33 per cent) warmbloods. In contrast with the outbreak of EVA in the UK in 1993, no signs of disease typical of EAV infection were reported during these investigations, even in mares test mated to stallions shedding the virus.  相似文献   

3.
Limited research has been undertaken to determine the impact of horse age, sex, and number of riders on horse performance in British Eventing (BE) horse trials. Improved understanding of this can aid professionals in planning a competition horse’s career. To investigate the impact of age, sex, and number of riders on the peak performance of horses at each of the main levels of BE competitions. The best score from each horse competing in BE horse trials in the years 2008–2018 was recorded, and principal component and hierarchical cluster analysis was performed. Basic data analysis was used to identify variables associated with particular better-performing clusters of horses. The interplay of the combinatory variables was then used to map out the trends in career trajectory for horses competing at each level of competition in the best-performing and worst-performing clusters. The peak performance of mares was worse than geldings and stallions at all levels. At Novice to Advanced, stallions did not perform as consistently with multiple riders as geldings. The age at which the best-performing groups peaked was similar for mares and geldings in all classes, although stallions peaked at an older age than mares and geldings at Novice and Intermediate level. All horses were a minimum of 4-years-old at the time of competition, as per BE rules.  相似文献   

4.
Five experiments were performed to evaluate the effects of dexamethasone (DEX), gender, and testosterone on plasma leptin concentrations in horses. In experiment 1, plasma leptin, insulin, glucose, and IGF-1 concentrations were increased (P < 0.01) in stallions following five daily injections of DEX (125 microg/kg BW). In experiment 2, leptin concentrations increased (P < 0.01) in mares, geldings, and stallions following a single injection of DEX, and the response was greater (P < 0.01) in mares and geldings than in stallions. The gender effect was confounded by differences in body condition scores and diet; however, based on stepwise regression analysis, both BCS and gender were significant sources of variation in the best fit model for pre-DEX leptin concentrations (R(2) = 0.65) and for maximum leptin response to DEX (R(2) = 0.75). In experiment 3, in which mares and stallions were pair-matched based on age and body condition and fed similar diets, mares again had higher (P < 0.01) leptin concentrations than stallions after DEX treatment as used in experiment 2. In experiment 4, there was no difference (P > 0.1) in plasma leptin response in mares following four single-injection doses of DEX from 15.6 to 125 microg/kg BW. In experiment 5, treatment of mares with testosterone propionate every other day for 5 days did not alter (P > 0.1) plasma leptin concentrations or the leptin response to DEX. In conclusion, multiple injections of DEX increase leptin concentrations in stallions, as does a single injection in mares (as low as 15.6 microg/kg BW), geldings and stallions. The greater leptin levels observed in mares and geldings relative to stallions were due partially to their greater body condition and partially to the presence of hyperleptinemic individuals; however, even after accounting for body condition and diet, mares still had greater leptin concentrations than stallions after DEX administration. Elevation of testosterone levels in mares for approximately 10 days did not alter leptin concentrations in mares.  相似文献   

5.
This study examined the influence of sex steroid hormones on lipid metabolism in horses. The group of 34 clinically healthy Standardbred trotters aged 2 to 4 years was studied during an exercise test. The horses were divided into groups according to their sex. These groups were: 11 stallions, 16 mares, and seven geldings. Concentrations of testosterone, 17-β-estradiol, leptin, ghrelin, glycerol, free fatty acids (FFA), and triacylglycerols (TG) were measured in plasma obtained from blood samples taken at rest and after the end of the exercise. At rest, plasma ghrelin concentration was significantly higher in geldings than in stallions and mares (1,541 ± 206 vs 1,280 ± 288 and 1,310 ± 267 pg/mL, respectively; P = .012). Leptin was lower in geldings than in mares (2.65 ± 0.93 vs 4.70 ± 2.31 ng/mL; P = .036). The post-exercise rise in plasma ghrelin and TG concentrations was significantly higher in mares than in geldings (+220 ± 330 vs -25 ± 206 pg/mL; P = .049 and 0.31 ± 0.14 vs 0.13 ± 0.15 mmol/L; P = .016, respectively). The increase in plasma FFA level was higher in geldings than in stallions (535 ± 178 vs 334 ± 191 μmol/L, P = .046). In conclusion, lipolysis rate in geldings is higher than in noncastrated trotters.  相似文献   

6.
Plasma concentrations of plasminogen were determined in 28 clinically normal horses, including 13 adult geldings, five non-pregnant mares, five pregnant mares and five yearlings (two fillies, three geldings). Plasminogen was quantitated by a chromogenic assay based on activation of plasmin by excess urokinase. The overall mean plasma plasminogen for these horses was 2.94 +/- 0.54 CTA units (casein units, as defined by the Committee on Thrombolytic Agents) per ml. There were no significant differences in mean plasma plasminogen values among adult geldings, non-pregnant mares, pregnant mares or yearling horses (P greater than 0.05).  相似文献   

7.
Pituitary and serum from 86 male or female horses of various reproductive states were collected in the normal breeding season (summer) and in the nonbreeding season (winter) at a commercial slaughterhouse. Concentrations of prolactin (PRL), luteinizing hormone (LH) and follicle stimulating hormone (FSH) were measured by radioimmunoassay. Concentrations of pregnant mare serum gonadotropin and reproductive steroids in serum and gross appearance of the reproductive tract and gonads were used to catagorize reproductive state. Concentrations of PRL were higher (P less than .01) in summer than in winter in pituitary and serum of mares, stallions and geldings. In summer, mares had higher (P less than .01) concentrations of PRL in serum than stallions. In mares, concentrations of LH in pituitary were higher (P less than .05) in summer than in winter. Concentrations of LH in serum were higher (P less than .01) in summer than in winter in mares and geldings, higher (P less than .01) in mares than in stallions in summer, higher (P less than .01) in geldings than in stallions in summer and higher (P less than .01) in mares with low serum progesterone (P) concentrations than in mares with high P concentrations in summer. Concentrations of FSH in pituitary and serum did not differ between summer and winter for any type of horse.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

8.
A questionnaire was used to determine the incidence of exertional rhabdomyolysis and the factors that might have contributed to its occurrence among 423 polo horses in 11 yards. The yards were selected at random, six of them with 111 horses, in north-eastern USA, and five with 312 horses in south-east England. During the 1999/2000 season the incidence of the condition was 7.3 per cent (9 per cent in the USA and 6.7 per cent in England). The incidence in mares was similar in the two countries, 8.4 per cent in the USA and 8.0 per cent in England, but the incidence in geldings in the USA (10 per cent) was much higher than in England (1.5 per cent). A more excitable than average temperament was reported in 71 per cent of the horses with the condition, and most cases occurred after a game (chukka) in which the horse was perceived to be not fit enough for the level of play demanded. Sixty-four per cent of the cases occurred early in the season and on average each episode resulted in the loss of 7.6 training days.  相似文献   

9.
The aim of this study was to evaluate the potential usefulness of the database maintained by the Swedish insurance company Agria for providing mortality statistics on Swedish horses. Mortality statistics (incidence rates and survival) were calculated, both crudely and stratified by sex, age, breed, breed group and diagnosis, for the horses with complete life insurance, which covers most health problems. The total mortality was 415 (95 per cent confidence interval [CI] 399 to 432) deaths per 10,000 horse-years at risk, and the diagnostic mortality, including only deaths with an assigned diagnosis, was 370 (95 per cent CI 355 to 386) deaths per 10,000 horse-years at risk. The diagnostic mortality of geldings was 459 (95 per cent CI 431 to 487), of mares 345 (95 per cent CI 322 to 365) and of stallions 214 (95 per cent CI 182 to 247) deaths per 10,000 horse-years at risk. The mortality rates increased with age and differed widely between breeds. Survival analysis showed that the median age at death of the horses enrolled before they were one year of age was 18.8 years. The most common cause of death or euthanasia was joint problems, which were responsible for 140 (95 per cent CI 130 to 149) deaths per 10,000 horse-years at risk. The results of multivariable models developed by using Poisson regression generally agreed well with the crude results.  相似文献   

10.
Three experiments were performed to test the following hypotheses: 1) stallions and/or progesterone-estradiol-treated geldings could serve as models for the effects of a single implant of the GnRH analog, deslorelin acetate, on LH and FSH secretion by mares; and 2) multiple implants of deslorelin acetate could be used as a means of inducing ovarian atrophy in mares for future study of the mechanisms involved in the atrophy observed in some mares after a single implant. In Exp. 1, nine light horse stallions received either a single deslorelin implant (n = 5) or a sham injection (n = 4) on d 0. In Exp. 2, 12 geldings received daily injections of progesterone on d -20 through -4, followed by twice-daily injections of estradiol on d -2 to 0. On the morning of d 0, geldings received either a single deslorelin implant (n = 6) or a sham injection (n = 6). Daily injections of progesterone were resumed on d 2 through 15. In Exp. 1, plasma LH and FSH were elevated (P < 0.05) in the treatment group relative to controls at 4, 8, and 12 h after implant insertion. In the treated stallions, FSH was decreased (P < 0.05) on d 3 to 13, and LH was decreased on d 6 to 13. In Exp. 2, plasma LH and FSH were elevated (P < 0.05) at 4,8, and 12 h after deslorelin implant insertion. Plasma LH was suppressed (P < 0.05) below controls on d 2 to 7, 9, and 11 to 15; plasma FSH was suppressed (P < 0.05) on d 4 to 15. In Exp. 3, 21 mares were used to determine whether multiple doses of deslorelin would cause ovarian atrophy. Mares received one of three treatments: 1) sham injections; 2) three implants on the first day; or 3) one implant per day for 3 d (n = 7 per group). Treatment with multiple implants increased (P < 0.05) the interovulatory interval by 14.8 d and suppressed (P < 0.01) LH and FSH concentrations for approximately 25 d; no mare exhibited ovarian atrophy. In conclusion, after an initial short-term increase in LH and FSH secretion, deslorelin implants caused long-term suppression of both gonadotropins in stallions as well as in geldings treated with progesterone and estradiol to mimic the estrous cycle. It is likely that either of these models may be useful for further study of this suppression in horses. Although multiple implants in mares suppressed gonadotropin secretion longer than a single implant, the lack of ovarian atrophy indicates that the atrophy observed after a single implant in previous experiments was likely due to the susceptibility of individual mares.  相似文献   

11.
Of 508 four-year-old coldblooded trotters examined for carpitis, 135 (27%) had the condition. Thirty horses had unilateral carpitis on the left frontlimb, 52 on the right frontlimb and 53 had bilateral carpitis. Of these horses, 105 were stallions, 135 were geldings and 269 were mares. The prevalence of carpitis in these three groups was 25%, 25% and 28%, respectively.Information was obtained on the training regimes in four periods of the life of 378 horses. The odds ratios for the training variables were of the same order in all four periods. In logistic regression analyses on the training variables for the first period for the variable percentage of carpitis within each progeny group (sire index), the odds ratio corresponding to a 10% increase in sire index was 1.7 (1.4, 2.1) (95% confidence interval of the odds ratio). The odds ratios for leaving the horses out in a paddock, walking in a jogcart and fast training, or not in each case, were 0.4 (0.2, 0.9), 2.5 (1.2, 5.3) and 2.0 (0.9, 4.4), respectively. This implies a decreased risk of developing carpitis for horses left out in a paddock as a two-year-old, and a 2.5 and 2.0 times increased risk of carpitis occuring in horses exposed to walking in a jogcart and fast training, respectively.Information on the feeding regimes during the first, second and third year collected by a questionnaire revealed no association with carpitis beyond that which could be ascribed to chance. The rations offered were within normal ranges except for calcium, which was below recommended levels.  相似文献   

12.
Insulin-like growth factor-1 could be a useful marker in the horse for diagnostic, selection, or forensic purposes, provided its physiological regulation is well understood. The objective of this study was to investigate factors, such as acute exercise, fitness training, time of day, sex, and age, that may influence serum IGF-1 in normal, healthy horses. Throughout a 9-wk training program, 6 geldings maintained a mean (+/- SEM) IGF-1 concentration of 302 +/- 29 ng/mL. Moderate or high intensity exercise had no effect on IGF-1 concentrations, when pre- and postexercise values were compared. Over a 24-h period, there was some variation in IGF-1 concentrations but no clear diurnal rhythm. Concentrations of IGF-1 were measured in a large population of thoroughbred horses (1,880) on 3 continents. The population deviated slightly from a normal distribution (P < 0.001) because of large IGF-1 concentrations in 10 horses. The global mean IGF-1 concentration was 310 +/- 2.2 ng/mL, with a greater mean value (P < 0.001) in gonad-intact males (336 +/- 5.6 ng/mL) than in females (303 +/- 3.2 ng/mL) or geldings (302 +/- 3.2 ng/mL). However, the greatest IGF-1 concentrations observed for all stallions, mares, and geldings were 627, 676, and 709 ng/mL, respectively. In mares and geldings, IGF-1 concentrations showed a gradual decrease with advancing age (P < 0.001), but the effect was much less marked in stallions. This study confirms that IGF-1 concentrations are stable, compared with GH concentrations, in the horse and that a meaningful measure of IGF-1 status can be obtained from a daily serum sample.  相似文献   

13.
Plasma antithrombin-III (AT-III) values were determined in 74 healthy horses by an automated spectrophotometric assay. The mean plasma AT-III value was 218% +/- 18% of normal human plasma. Plasma AT-III values did not differ significantly (P less than 0.05) among Thoroughbred, Standardbred, Quarter Horse, and other breeds or among mares, geldings, or stallions.  相似文献   

14.
Research on the racing performance of quarter horses has been used to develop genetic prediction summaries on all horses with at least one start on record at the American Quarter Horse Association. In the 1987 summary, records from a total of 212,065 horses were used to give genetic predictions on stallions, mares, geldings, fillies, and colts. A reduced animal model was used that incorporated the repeated records of individuals. The individual race was the contemporary group after the data were adjusted for distance, sex, and age. Estimates of heritability of .24 and repeatability of .32 suggest that increased racing performance can be achieved if the predictions are used by breeders. Continued research in variance component estimation includes the genetic covariances among the several distances, maternal influence, and genetic parameters for racing longevity.  相似文献   

15.
A national survey of headshaking in 254 horses was undertaken to describe the clinical signs of the condition as observed by horse owners. Principal component analysis was used to determine the underlying structure of 11 signs and the criteria by which the affected horses could be most effectively differentiated; the analysis suggested five components with a variance greater than one which together explained over 60 per cent of the total variance. Other analyses of the data indicated that headshaking could develop at any age and that twice as many males were affected as females; 64 per cent of the horses shook their heads seasonally and geldings were more likely than mares to be seasonally affected. Seasonal headshaking tended to be significantly worse on sunny days but improved on rainy days, windy days, at night and indoors.  相似文献   

16.
Ten stallions were used in a modified split-plot design involving four treatments and two handling methods. Treatments were: a) vision and olfaction not blocked; b) vision blocked, olfaction not blocked; c) vision not blocked, olfaction blocked; and d) vision and olfaction blocked. The methods of handling were: a) stallions turned loose in teasing area, and b) stallions handled on a lead shank. Stallions teased four estrous mares, four diestrous mares and four geldings. Criteria for evaluation of stallion behavior was duration of investigation (sec), of area as well as various portions of the stimulus animal's anatomy, and other pre-copulatory sexual behaviors (Table 1) in duration and frequency. Except for area investigation and no investigation, there were more frequent or longer responses when vision was not blocked compared to blocked (P<0.05). Events associated with display of flehmen and mounting activity were lower (P<0.05) when vision was blocked. Handling a stallion on a lead shank, while teasing, resulted in 23 longer or more frequent pre-copulatory sexual behaviors than when the stallions were loose. There were more frequent or longer (P<0.05) behavioral responses when stallions were handled on a lead shank and olfaction was not blocked. Events such as duration and number of flehmen responses were lower (P<0.05), and time of no investigation was longer (P<0.001) when olfaction was blocked. There was no difference (P>0.05) in the time spent inyestigating estrous mares, diestrous mares or geldings, except for number of flehmen responses. Number of flehmen responses to estrous mares was higher (P<0.05) than to diestrous mares, while number of flehmen responses to diestrous mares was higher (P<0.001) than to geldings. Blocking olfaction did not decrease frequency or duration of sexual behaviors as much as blocking vision (P<0.05), resulted in decreased (P<0.05) flehmen responses. Blocking vision significantly decreased (P<0.05) teasing behaviors, duration of erection, flehmen, and number of mounts regardless of stimulus animal. Stallions utilized visual stimuli to a greater extent than olfactory stimuli. Handling stallions on a lead shank appeared to enhance expression of precopulatory behavior compared to when the stallions were loose.  相似文献   

17.
Effects of furosemide on the racing times of Thoroughbreds   总被引:1,自引:0,他引:1  
The effects of furosemide on the racing times of 79 horses without exercise-induced pulmonary hemorrhage (EIPH) and 52 horses with EIPH were investigated. Racing times were adjusted to 1-mile equivalent racing times by 2 speed handicapping methods, and analysis of covariance was used to adjust actual racing times by winning time and distance for each race. All 3 methods of determining racing time indicated that geldings without EIPH had significantly faster racing times (P less than 0.05) when given furosemide before racing than when furosemide was not given before racing. Females and colts without EIPH were determined to have faster racing times when furosemide was given before racing, but the difference was not significant. Geldings with EIPH had significantly faster racing times (P = 0.0231) when given furosemide before racing, as determined by one of the speed handicapping methods. There was a strong correlation (range 0.9314 to 0.9751) between the 1-mile equivalent racing times, as determined by the 2 speed handicapping methods for horses with and without EIPH. Furosemide failed to prevent the development of EIPH in many horses that were previously considered to be EIPH-negative. When given furosemide, 62 (25.3%) of 235 EIPH-negative horses were EIPH-positive after racing. Furosemide had questionable efficacy for prevention of EIPH in known EIPH-positive horses. Thirty-two (61.5%) of 52 EIPH-positive horses given furosemide before a race remained EIPH-positive after that race.  相似文献   

18.
Reason for performing study: Current use of acepromazine in the anaesthetic management of male horses and ponies and associated risks are largely unknown. Objectives: To explore anaesthetic acepromazine use and related adverse effects in the male horse. Methods: Of 8533 anaesthetised horses and ponies medical records of male animals treated perianaesthetically with acepromazine were reviewed. Demographic data, time and dose of acepromazine administration, co‐administered drugs, quality of induction and recovery from anaesthesia, arterial blood pressures, and occurrence of penile dysfunction were recorded. Practising ACVA and ECVAA diplomates were polled on the use of acepromazine and its effects on blood pressure and penile dysfunction in the equine. Results: Of all animals, 12% females and 11% males (n = 575 including 42% stallions) received perianaesthetic acepromazine, predominantly for premedication. Anaesthetic induction was smooth in 566 animals. Lowest mean arterial pressures averaged 65 ± 9 mmHg. Recovery was good or very good in 70% of all animals and 74% stood after 1–2 attempts. In 14 horses (2.4%; 7 stallions, 7 geldings), penile prolapse occurred for 0.5–4 h and in one stallion (0.2%) for >12 but <18 h post recovery. Most surveyed anaesthesiologists use acepromazine in stallions (occasionally 63%; frequently 17%) but more frequently in geldings (occasionally 34%; frequently 59%) and mares (occasionally 38%; frequently 59%), primarily for premedication with other sedatives and analgesics. Persistent intraoperative hypotension was not frequently reported. Only 5% of surveyed anaesthesiologists recall penile prolapse post acepromazine administration lasting for >12 h and only one recalls 3 cases of irreversible penile prolapse in 20 years of anaesthesia practice. Conclusions and potential relevance: The extremely low risk of permanent penile dysfunction (≤1 in 10,000 cases) does not justify more restricted use of acepromazine in the intact male vs. geldings and mares.  相似文献   

19.
Strangulating volvulus of the ascending colon in horses   总被引:2,自引:0,他引:2  
Of 57 horses with strangulating volvulus of the ascending colon, 42 were mares (including 21 postparturient mares), 8 were stallions, and 7 were geldings. Volvulus occurred most frequently in the summer (n = 24) and spring (n = 17). Pain was evaluated as severe in 41 horses, moderate in 9, and mild in 4. The abdominal fluid from 30 horses varied from clear yellow in 19 horses, to cloudy yellow in 3 horses, and serosanguineous in 8 horses. Protein content and nucleated cell count in the abdominal fluid were 2.5 +/- 1 g/dl and 1,000 +/- 900 microliters, respectively. Fifty horses had greater than or equal to 360 degrees volvulus and 7 had a 270 degrees volvulus, with 49 occurring in a counterclockwise direction. The site of volvulus in all horses was at the mesenteric attachment of the colon, except for a 360 degrees volvulus at the sternal and diaphragmatic flexures in 1 horse. Survival rates for horses with a greater than or equal to 360 degrees and a 270 degrees volvulus were 36% and 71%, respectively. The difference in survival rates reflected the severe vascular occlusion in the colon of horses with greater than or equal to 360 degrees volvulus. In nonsurvivors, hemorrhage in the submucosa and lamina propria (P less than 0.005) and edema in the submucosa (P less than 0.01) were greater than those in survivors. In nonsurvivors, greater than 97% of the superficial epithelium was lost. In horses that survived, only 60% of the cells were lost or degenerated.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

20.
This article reviews the literature on equine atypical myopathy (AM), an acute, severe rhabdomyolysis that occurs in horses at pasture. The prevalence, mortality, clinical signs, pathology, potential aetiology, typical aspects, diagnosis, treatment, and prognosis are described. Horse management, characteristic weather conditions, and possible preventive measures are also discussed. In addition, the characteristics of 54 highly probable or confirmed cases of equine AM occurring between autumn 2009 (27 cases) and spring 2010 (27 cases) in the Netherlands are described. Of the 54 affected horses, nineteen were mares, eleven geldings, and eight stallions; the sex of the other sixteen horses was not recorded. The mortality rate (74.5%) was in the same range as that reported in earlier studies. Many cases were reported at about the same time. Thirty-five horses had been pastured near maple trees, and in fifteen cases the maple trees were known to be infected with the fungus Rhytisma acerinum.  相似文献   

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