The Horse:Your Guide To Equine Health Care provides monthly equine health care information to horse owners, breeders, veterinarians, barn/farm managers, trainer/riding instructors, and others involved in the hands-on care of the horse.
Issue link: https://thehorse.epubxp.com/i/570682
30 TheHorse.com THE HORSE October 2015 to the esophagus (the top half). While traditionally ulcers were thought to occur most commonly in the squamous region, it is becoming increasingly apparent that ulcers can also affect the glandular region. "Equine squamous gastric disease ( ESGD) has been reported in 50% to 100% of performance horses in various studies, while the prevalence of equine glandular gastric disease (EGGD) has been reported as being between 30% to 65% in a number of different horse types," Sykes said. To date, very little information has been published on the prevalence of either in feral horses. So Sykes and colleagues from Oxford Brookes University, in Oxfordshire, and Abingdon and Whitney College, in Abing- don, in the U.K., evaluated the prevalence of ESGD and EGGD in feral (in this case, free-ranging Dartmoor and Exmoor horses with little to no human contact) and domestic horses taken to a local abat- toir (slaughterhouse). Sykes graded the lesions in all of the processed horses' stomachs on a scale of 0 to 4 (with 4 being most severe) via pho- tos; he was blinded to whether the horses were feral or domestic. He classified horses as being ESGD- or EGGD-positive (scoring 2 or higher for each region) or negative (scoring 1 or less). The team evaluated data on 51 domes- tic and 27 feral horses, determining that: ■ 22.2% of feral horses and 60.8% of domestic horses had ESGD; and ■ 29.6% of feral horses and 70.6% of domestic horses had EGGD. While researchers have long known that the risk of ESGD rises with increas- ing human intervention, "this report is, to the authors' knowledge, the first documenting that a similar effect may be present for EGGD. "The … prevalence of squamous gastric disease in the feral horses was surpris- ing," Sykes said. "However, it has been previously shown that squamous ulcers may develop rapidly with fasting and transport, both of which the feral horses were exposed to." He said finding glandular gastric disease in 29.6% of feral horses was also surprising. "Factors such as fasting and transport … to date have not been dem- onstrated to cause glandular disease," he said. "The findings of this study support the idea that factors imposed through domestication and intensive management (such as frequent stabling or long periods without forage) increase the risk of both ESGD and EGGD. Risk factors for squamous ulcers are well-described, and simple management changes such as per- mitting free-choice access to good-quality roughage (forage), increasing pasture turnout, and reducing grain intake are likely to reduce the likelihood of disease." In contrast, he said, we still don't understand glandular ulcer risk factors. "The findings of this study suggest that in- tensive management may play an overall role in increasing the risk of disease, but the individual risk factors are not known," Sykes said. "As such, it is not possible at this point in time to make specific recom- mendations to reduce the risk of EGGD. It is logical to follow the dietary and lifestyle changes advocated for the prevention of ESGD, but their efficacy in reducing the risk of EGGD is questionable." Cushing's Characteristics, Clinical Signs at Diagnosis Veterinarians and horse owners re- cently enrolled nearly a thousand horses of all breeds and ages showing possible recognizable characteristics of PPID in a nationwide study. Researchers confirmed some suspected patterns and identified others they considered surprising in two scientific papers based on the data. Steve Grubbs, DVM, PhD, Dipl. ACVIM, of Boehringer Ingelheim Vet- medica Inc., in St. Joseph, Missouri, and colleagues conducted the epidemiological study. The team determined that 515 of the horses had complete case information and could be included. For the first paper, on the epidemiolog- ic characteristics of horses with PPID at initial diagnosis, Grubbs said study horses had to have at least one of the following signs: generalized or regional hypertricho- sis, muscle wasting, abnormal fat distribu- tion, potbelly/weight gain, laminitis of unknown origin, polyuria, polydipsia, susceptibility to infections, abnormal sweating, decreased athletic behavior/leth- argy, and/or inappropriate lactation. Researchers gathered signalment and demographic data (age, sex, breed, loca- tion) on each horse at initial veterinary visit, collected a case history, and con- ducted a physical exam. Then they drew blood to measure basal (resting) ACTH, fasting insulin, and glucose levels—which can point to PPID or to insulin resistance ACVIMForum Researchers compared feral horses' ulcer rates to those of domestic ones and found surprising results. ISTOCK.COM Researchers found gastric ulcers in 26.9% of feral horses studied