A survey of health care and disease in geriatric horses aged 30 years or older

This study reports on aspects of preventive health care and on the prevalence of disease in geriatric (≥30 years old) horses and ponies in North-West England and North Wales. Of 128 questionnaires mailed to horse owners, 87 useable responses were received and 69 horses were subject to veterinary examination. Of the animals examined, 16% were underweight with body condition scores (BCS)<2/5, and 10% were overweight (BCS>3/5). This contrasted with the owner responses that reported 23% of the animals surveyed to be underweight and only 3% to be overweight. When assessed at trot, 77% of the horses were lame on at least one limb, with 97% having a reduced range of motion in at least one joint. Only 16% of these animals were reported by owners to have been lame within the previous 12 months. Owner-reported changes to hair coat were significantly associated with hirsutism or abnormal moulting detected at clinical examination (39%). At least one ophthalmic lesion was identified in all of the horses and ponies examined and 17% of owners reported that their animal had experienced visual problems within the previous year. Although dental abnormalities were detected in all animals where an oral examination was performed, only 42% of owners reported that their horse suffered from a known dental disorder. In general, despite a high prevalence of disease detected in these geriatric animals and with the majority having multiple abnormalities at clinical examination, there was under-reporting/under-recognition of these health problems by owners.     

Effect of management factors and blood metabolites during the rearing period on growth in dairy heifers on UK farms

Growth rates during rearing affect the age and body weight (BW) of replacement heifers at first calving. Diet and disease can affect growth via altered metabolic hormone concentrations, but are difficult to monitor accurately on commercial farms. This study investigated the effect of management and metabolic indices (IGF-I, insulin, glucose and urea) on the growth rate of 509 Holstein-Friesian heifers on 19 UK dairy farms. Size (BW, heart girth, height and crown-rump length) was measured at approximately 1, 6 and 15 months. The mean daily weight gain up to 6 months for all calves was 0.77 kg/day, with extreme variability both between cohorts of calves (range 0.49–1.02 kg/day) and between individual calves within farms (range 0.45–1.13 kg/day). Growth was enhanced by supplemental colostrum, by milk replacer as opposed to whole milk and by ad libitum milk feeding and was reduced by gradual weaning and dehorning after weaning. Larger group size slowed growth before weaning (>6 calves) but increased it post-weaning (>20 calves). These management differences were reflected in altered plasma IGF-I concentrations, which were positively associated with growth throughout the rearing period. Larger calves at 1 month had a greater weight gain up to 6 months. Sub-optimum growth of some heifers within each cohort was established at an early age and resulted in animals reaching the start of breeding at an inadequate size (BW range 209–498 kg at 15 months). This could be alleviated by altered management strategies and improved monitoring of growing heifers.     

Refrigerated Storage of Red Deer Epididymal Spermatozoa in the Epididymis, Diluted and with Vitamin C Supplementation

We have approached the problem of refrigerated storage of epididymal sperm samples from red deer by comparing three options: storing the genital (testicles within the scrotum), diluting the semen in extender or diluting the semen in extender supplemented with an anti-oxidant. Twenty-nine pairs of testes were collected. Spermatozoa from one of each of the pairs were immediately recovered, and diluted to 400 × 10⁶ sperm/ml in Tris-citrate-fructose with 20% egg yolk. Control group was stored as such, and Anti-oxidant group was supplemented with 0.8 m m vitamin C. The remaining epididymides and the diluted samples were stored at 5°C and spermatozoa were analysed at 0, 24, 96 and 192 h for: motility [computer-assisted semen analysis (CASA)], acrosomal integrity, sperm viability (eosine/nigrosine staining), normal tails and chromatin status [sperm chromatin structure assay (SCSA)]. In general, seminal quality decreased with storage time. Vitamin C supported progressive motility better at 24 h (median 42% vs 23% Control and 15% epididymis), reduced the incidence of tail abnormalities and protected chromatin. Storing the semen in the epididymis slowed down motility loss, but slightly increased the occurrence of tail abnormalities and viability was lower at 192 h. However, regarding chromatin status, sperm stored in the epididymis was protected similarly to those diluted in the medium supplemented with vitamin C. Although the differences between the three groups were small, there were some advantages in supplementing the extender with vitamin C. Besides, refrigerating the epididymis may be a good option when immediate processing is not available.     

Incidence and risk factors associated with exertional rhabdomyolysis syndrome in National Hunt racehorses in Great Britain

A telephone survey of 51 National Hunt racing yards with 1140 horses in training was made in April and May 2003 to establish the incidence of exertional rhabdomyolysis syndrome during the previous year. A case-control study was used to investigate the risk factors for the syndrome in eight yards selected on the basis that cases had been confirmed by the analysis of serum muscle enzymes. The overall incidence of syndrome was 6.1 cases per 100 horses per year, and 55 per cent of the yards reported at least one case. The risk factors identified were sex, the average length of the training gallop, and the type of horse (steeplechaser, bumper/unraced or hurdler). There were no significant associations with the horses' temperament, age or Timeform rating.     

Efficacy of trilostane for the treatment of equine Cushing's syndrome

REASONS FOR PERFORMING STUDY: Trilostane, a competitive 3-beta hydroxysteroid dehydrogenase inhibitor, has been used successfully to control clinical signs and cortisol excess in canine pituitary dependent hyperadrenocorticism. OBJECTIVES: Trilostane was evaluated for its efficacy in resolving clinical and clinicopathological abnormalities of equine Cushing's syndrome (ECS) and to assess its safety. METHODS: Twenty horses (mean age 21 years) diagnosed with ECS were followed for 1 or 2 years. Affected horses received 0.4-1 mg/kg (mean 0.5 mg/kg) trilostane once daily. RESULTS: Clinical signs assessed over 1 or 2 years, showed a reduction in lethargy in all horses post treatment. Polyuria and/or polydipsia, present in 11 horses, was reduced in all after treatment. Recurrent or chronic laminitis, present in 16 horses, improved in 13/16 (81%) of cases. There were no side effects reported. Combined dexamethasone suppression and thyrotropin releasing hormone (TRH) stimulation tests were significantly different before and 30 days following therapy. There was a significant reduction (P = 0.01) of cortisol following TRH administration before (160 +/- 53.0 nmol/l) and after (130 +/- 46.1 nmol/l) trilostane. CONCLUSIONS: Trilostane caused improvement in clinical signs in horses, without side effects, and a corresponding decrease in cortisol response to TRH administration. POTENTIAL RELEVANCE: Trilostane may be a useful therapy for the treatment of ECS. Further work comparing the effects of trilostane and pergolide is warranted.     

Incidence of exertional rhabdomyolysis in polo horses in the USA and the United Kingdom in the 1999/2000 season

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.     

Epididymitis in rams: effect of vaccination and culling on the clinical incidence of the disease.

Ram epidiymitis caused by Brucella ovis can be effective controlled by an annual program combining rigorous culling clinically affected animals and appropriate vaccination of the remaining animals. Yearling rams purchased or saved as replacement breeders should be immunized at 4-5 months of age by two injections of Br. ovis bacterin spaced 3-6 weeks apart. Annually, approximately one month prior to the breeding season, all rams, replacements and older breeders as well, should be carefully examined by palpation of the scrotal contents. Every ram evidencing an abnormality should be culled as a breeder. All the remaining rams should receive a "booster" injection of Br. ovis bacterin.