Summary: Reasons for performing study: Metformin is a potential therapeutic agent for the treatment of insulin resistance ( IR ). In laboratory animals, orally administered metformin reduces intestinal glucose absorption and may therefore affect insulinaemic responses to oral carbohydrate ingestion. Objectives: To determine whether pretreatment with metformin reduces plasma glucose concentration and insulin responses following consumption of dextrose in horses. Study design: Therapeutic cross‐over study. Methods: Seven healthy Standardbred and Thoroughbred geldings were subjected to an oral dextrose challenge test on 4 occasions: with and without metformin, before and after induction of IR with dexamethasone. Metformin was administered by nasogastric tube at 30 mg/kg bwt 1 h before administration of dextrose. Glucose and insulin concentrations in plasma/serum were measured at regular intervals during each test. Linear mixed models were specified for each predetermined outcome variable, and for each model the ‘treatment’ was included as a fixed effect with 4 categorical levels (none, metformin, dexamethasone and dexamethasone with metformin) and horse accounted for as a random effect. Results: In healthy horses, the administration of metformin resulted in a statistically significant reduction in peak glucose concentration (P = 0.002), area under the glucose curve (P<0.001) and insulin concentration 120 min after dextrose administration (P = 0.011). Following the induction of IR , administration of metformin was associated with significant differences in peak glucose concentration (P<0.001), the percentage increase in glucose concentration (P = 0.010), the area under the glucose curve (P<0.001) and insulin concentration at 120 min (P = 0.034) and 150 min after dextrose administration (P = 0.014). Conclusions: Metformin resulted in reduced glycaemic and insulinaemic responses both in healthy horses and in horses with experimentally induced IR . Potential relevance: Metformin may benefit horses with naturally acquired IR by reducing glycaemic and insulinaemic responses to dietary nonstructural carbohydrates. Further investigations into the mechanisms of action of metformin in horses and controlled clinical trials are warranted.

Equine obesity is now so common that is has become accepted by many as the norm (Owers and Chubbock, 2012). Rates of obesity may be as high as 70% in some populations and obesity is often associated with morbidities that may ultimately result in mortality. Obesity is a common feature in animals diagnosed with equine metabolic syndrome, a conflation of metabolic disturbances including insulin dysregulation, which may lead to laminitis. Obesity is a risk factor for insulin dysregulation and is therefore implicated in laminitis risk. In addition to laminitis, adverse consequences of obesity include orthopaedic disease, hyperlipaemia, hyperthermia, infertility and poor performance. Over time, perception of what constitutes a healthy body condition in horses has shifted, with the result that potentially harmful excess adiposity may not be recognised by owners or those working in the equine industry (Owers and Chubbock, 2012). In addition, increasing numbers of equines are kept as companions rather than athletes and live relatively inactive lifestyles favouring the development of obesity. Finally, owners of leisure horses often think their horses are working hard when, in reality, their exertions have minimal impact on their energy requirements. Despite increasing awareness within the veterinary profession and equine industry of the impact of obesity on equine welfare, little progress seems to have been made in tackling it. This document was commissioned in order to provide veterinary surgeons with up-to-date information on equine obesity and to equip them to tackle it within their own practices. Recommendations were developed using an informal two-round Delphi process, considering published and unpublished research relating to equine obesity using a round table forum and online discussion. Where research evidence was conflicting or absent, collective expert opinion based on the clinical experience of the group was applied. The opinions expressed are the consensus of views expressed by the authors. Where agreement was not reached, opposing views are presented such that readers can understand the arguments fully. The document is focused on the management of horses and ponies; while much of the information herein is applicable to donkeys it is important to recognise that the metabolism and management of donkeys are different and further research is required before specific recommendations can be made. The expert group was organised by UK-Vet Equine with sponsorship from Baileys Horse Feeds.

The European College of Equine Internal Medicine (ECEIM) consensus statement recently made the distinction between disease of the squamous mucosa (Equine Squamous Gastric Disease; ESGD) and of the glandular mucosa (Equine Glandular Gastric Disease; EGGD) (Sykes et al, 2015a). Since its publication, a number of reports have furthered understanding of the pathology and management of EGGD, such that new clinical guidelines for the management of this condition were considered necessary. The following guidelines are the consensus views of subject specialist representing authors of the ECEIM consensus statement, authors of recent clinical research, and clinical specialists active in the management of horses with this condition. The recommendations were developed using an informal two-round Delphi process, considering published and unpublished research relating to EGGD using a round table forum and online discussion. Where research evidence was conflicting or absent, collective expert opinion based on the clinical experience of the group was applied. The opinions expressed are the consensus of views expressed by the authors. The expert group was organised by UK-Vet Equine with sponsorship from Luoda Pharma.

In equids, chorioptic mange is a common dermatitis for which there are no licensed medications in the uk . Doramectin and fipronil are licensed for the control of ectoparasites in other species and were evaluated for the treatment of 17 cases of chorioptic mange in 13 equids. Equids were included if clinical findings were indicative of chorioptic mange, chorioptes mites were positively identified and concurrent disease that could affect response to disease was not evident. A random number table was used to allocate subjects to receive doramectin (group D, eight animals) or fipronil (group F, nine animals). Each of the horses in group D were given 0·3 mg/kg doramectin (Dectomax; Pfizer) on two occasions 14 days apart by subcutaneous injection. All limbs of the horses in group F were sprayed with fipronil 0·25 per cent solution (Frontline; Merial) to the level of the stifles and elbows. Both groups were examined on the day of treatment and 14 and 28 days later to assess the behavioural signs of pruritus and the severity of the dermatological lesions. Acetate tape impressions were collected from the distal limbs and the degree of mite infestation was assessed. By day 28 there were no behavioural signs of chorioptic mange in any of the animals, and there were significant reductions in the numbers of mites in both groups. However, there were no significant reductions in the mean lesion score in either group. There was no significant difference between the effectiveness of the two treatments.