Short-Term Omeprazole Use Does Not Affect Serum Calcium Concentrations and Bone Density in Horses

Equine Gastric Ulcer Syndrome: An Update on Current Knowledge

Equine Gastric Ulcer Syndrome (EGUS) is a term that has been used since 1999, initially being used to describe all gastric mucosal disease in horses. Since this time, the identification of two distinct main disease entities of the equine gastric mucosa have been described under the umbrella of EGUS; these are Equine Squamous Gastric Disease (ESGD) and Equine Glandular Gastric Disease (EGGD). In 2015 the European College of Equine Internal Medicine (ECEIM) released a consensus statement defining these disease entities. This document highlighted the lack of evidence surrounding EGGD compared to ESGD, and identified knowledge gaps for further research to be directed. Subsequently, many studies on EGGD have been published, especially on pathophysiology, diagnosis, and treatment. This article updates current knowledge on both ESGD and EGGD as understanding has evolved since the last large-scale review.

Equine Squamous Gastric Disease: Prevalence, Impact and Management

This narrative review explores the etiopathogenesis, clinical signs, diagnosis and treatment of ESGD (equine squamous gastric disease) and discusses the impact of this commonly encountered condition on the equine industry. ESGD refers specifically to peptic injury of the squamous mucosa of the stomach. Prevalence is highest in performance horses, but the disease has been documented across many breeds and ages, including in feral horses and foals. The pathogenesis of ESGD is well understood. Intensive management and exercise are important factors that contribute to a disruption of the normal stratification of gastric pH. This results in exposure of the vulnerable squamous mucosa to acid, leading to ulceration. Clinical signs are variable and there is little evidence to support a direct association between reported signs and the presence or absence of lesions seen on gastroscopy. Management is aimed at acid suppression and mitigation of known risk factors.

What Would Be Good for All Veterinarians to Know About Equine Nutrition

Nutrition and management have enabling and supporting roles to play in the health, welfare, and performance of equines. Poor or inappropriate nutrition may therefore impose limits on an animal's ability to perform and adversely affect health and welfare. Understanding the gastrointestinal tract from a nutrition perspective can help to reduce the risk of certain clinical problems. This article outlines key factors with respect to the equine digestive tract and discusses relevant aspects of ration formation. Forage is highlighted, because inappropriate forage provision is one of the key limitations in many horse diets.

Omeprazole Reduces Calcium Digestibility in Thoroughbred Horses

Proton pump inhibitors such as omeprazole reduce nutrient digestibility in humans. This study determined the effect of omeprazole on the digestibility of diets containing limestone or marine-derived calcium (BMC) and to assess changes in blood parameters associated with gastric acid production and calcium status in horses. Thoroughbreds were used to evaluate the digestibility of diets containing different calcium sources with or without omeprazole over four 21-day periods. Each 21-day period had a 15-day diet adaptation phase followed by a 6-day collection phase, consisting of a 5-day total fecal collection period and a final day for gastroscopy and blood sampling. Horses were fed the same diet with either 60 g/d BMC or 50 g/d limestone, so the total diet provided ∼45 g calcium. Horses on omeprazole were given GastroGard once daily for the final 14 day of each 21-day period, which supplied 3.91 ± 0.17 mg/kg BW/d of omeprazole. On day 21, blood samples were taken and gastric fluid pH was measured 8 hour after omeprazole administration. Omeprazole had a profound effect on gastric fluid pH in omeprazole-treated horses compared with nontreated horses. Serum gastrin doubled in omeprazole-treated horses compared with nontreated horses. Omeprazole and calcium source did not affect digestibility of phosphorus, magnesium, potassium, sodium, iron, copper, zinc, or manganese but did affect calcium digestibility. Omeprazole reduced apparent calcium digestibility from 52.0% to 41.4% in limestone and from 55.1% to 46.5% in BMC, equalling a 20.3% and 15.6% decrease in calcium digestibility in the limestone and BMC, respectively. Mineral source had a significant effect on calcium digestibility with BMC at 50.8% and limestone at 46.7%.

Omeprazole and its impact on mineral absorption in horses

Omeprazole is commonly used to treat and prevent ulcers in horses. As a proton-pump inhibitor, and with absorption of calcium dependent on gastric acidity, there is concern that reduction in acidity may interfere with calcium absorption. The present study was conducted to evaluate whether daily omeprazole administration can influence bone health in horses. Prior to commencement of treatment, 10 Standardbred geldings underwent endoscopic examinations for gastric ulcers and to determine gastric pH. They were fed a grass-hay diet. Three-day total collections of faeces and urine were performed to evaluate mineral balance. The left third metacarpus was radiographed to establish baseline values of mineral content by using a radiographic photo-densitometry technique to calculate radiographic bone aluminium equivalence, and blood samples were taken for examination of markers of bone metabolism. The horses were pair-matched and randomly assigned to either a treatment or the control group. Treated horses received omeprazole at the preventative dose (1 mg/kg bodyweight) and control horses received no medication for the duration of the 8-week study. They were housed in box stalls and had daily turnout on drylots. Endoscopy was performed again at the completion of the study, total collections were performed again at the middle and end of the study and blood samples were taken every 2 weeks. No meaningful treatment effects were found for ulcers, gastric pH, mineral balance, radiographic bone aluminium equivalence, or markers of bone formation. Daily administration of omeprazole did not appear to have any negative effects on indices of skeletal health measured in the study.