Adipose tissue dysfunction in obese horses with equine metabolic syndrome.

BACKGROUND: Obesity is a common feature of equine metabolic syndrome (EMS). In other species, obese adipose tissue shows pathological features such as adipocyte hypertrophy, fibrosis, inflammation and impaired insulin signalling all of which contribute to whole body insulin dysregulation. Such adipose tissue dysfunction has not been investigated in horses. OBJECTIVES: To determine if obese horses with EMS have adipose tissue dysfunction characterised by adipocyte hypertrophy, fibrosis, inflammation and altered insulin signalling. STUDY DESIGN: Cross-sectional post-mortem study. METHODS: Samples of peri-renal (visceral) and retroperitoneal adipose tissue were obtained at post-mortem from healthy horses (n = 9) and horses with EMS (n = 6). Samples were analysed to determine average adipocyte size, fibrotic content and expression of inflammatory and insulin signalling genes. RESULTS: Horses with metabolic syndrome showed marked adipocyte hypertrophy and increased expression of adipokines (leptin) and inflammatory cytokines (TNFα, IL1ß and CCL2) in both adipose tissue depots compared to healthy horses. There were no differences in fibrosis or expression of genes relating to insulin signalling between the groups. MAIN LIMITATIONS: Cases used in this study had advanced EMS and may represent the end stage of the condition; the design of the study is such that we were unable to relate the identified adipose tissue dysfunction to whole body insulin dysregulation. CONCLUSIONS: Horses with obesity and EMS have significant dysfunction of the peri-renal and retroperitoneal adipose tissue that may contribute to whole body insulin dysregulation.

Incidence and risk factors for exertional rhabdomyolysis in thoroughbred racehorses in the United Kingdom.

Telephone surveys of 34 racing yards with 1276 horses in training were made to establish the overall incidence of exertional rhabdomyolysis in the previous year. A case-control study was used to investigate the risk factors for the syndrome in 12 yards selected on the basis of the routine confirmation of diagnoses by the evaluation of the serum activities of creatine kinase and aspartate aminotransferase. The overall incidence of the syndrome was 6.7 per cent and 80 per cent of the trainers had at least one affected horse. In 74 per cent of the affected horses it frequently recurred, with an average of six lost training days per episode. Risk factors identified for the syndrome included being female, having a nervous, excitable temperament, and being two years old.

Otitis media caused by beta-lactamase-producing Branhamella (Neisseria) catarrhalis.

A beta-lactamase-producing Branhamella catarrhalis was isolated in pure culture from the right middle ear aspiration of an otitis media in a 3-month-old girl. The patient responded well to cefamandole treatment.