ABSTRACT
Gastric ulceration is a prevalent condition of racehorses. A number of models of gastric ulceration have been described, but none mimic the conditions of a horse in training. The objectives of this study were to determine whether gastric ulcers could be induced and maintained in a group of horses in simulated race training. In addition, serum cortisol was measured on a weekly basis to investigate the possibility that stress may be important in the pathogenesis of gastric ulceration. Thirty horses used in the trial were fed Bermuda grass hay and 6 kg of a concentrate diet, and exercised 6 days/week at speed over a distance of 1.6-2.4 km. Serum was collected and gastroendoscopic examinations performed on a weekly basis for the duration of the trial. All horses developed moderate to severe ulceration, and ulcers were maintained for the 56 day period of the trial. Only one horse had signs of abdominal discomfort, which resolved with minimal symptomatic treatment and without the use of anti-ulcer medications. Serum cortisol remained within reference ranges for the duration of the trial. Although there was some variation between the weekly examinations, serum cortisol concentrations were decreased from values obtained at the start of the trial. In this study ulcers developed without the administration of nonsteroidal anti-inflammatory agents or withholding of feed. This model provides a method to study the condition, and to investigate the effects of medications on the healing of ulcers in racehorses.
Subject(s)
Horse Diseases/etiology , Horse Diseases/physiopathology , Physical Conditioning, Animal , Stomach Ulcer/veterinary , Analysis of Variance , Animals , Breeding , Diet/veterinary , Female , Horse Diseases/blood , Horses , Hydrocortisone/blood , Male , Stomach Ulcer/blood , Stomach Ulcer/etiology , Stomach Ulcer/physiopathology , Stress, Physiological/complications , Stress, Physiological/veterinaryABSTRACT
A multicentre, blinded, randomised complete-block, field trial was conducted with 140 horses and foals age 4 weeks-28 years to determine if omeprazole paste is effective and safe in promoting healing of spontaneous gastric ulcers under a variety of field conditions and in different breeds and ages of horses. Horses in the study had gastric ulceration as determined by gastroscopy and were divided into replicates of 4 or 5 animals. One horse in each replicate was assigned randomly to receive an empty omeprazole syringe (sham-dosed control) and the remaining horses received omeprazole paste once daily for 28 days. Gastroscopy was repeated at the end of the study. Horses treated with omeprazole had significantly (P < 0.01) more improvement in ulcer scores at the end of the study compared with controls. Ulcers were improved in 32.4 and 99.0% of the control and omeprazole groups, respectively. Ulcers were completely healed in 8.9 and 86.7% of the control and omeprazole groups, respectively. Under typical field conditions, omeprazole was effective at enhancing healing of spontaneous gastric ulcers in horses of a variety of ages and breeds.
Subject(s)
Enzyme Inhibitors/therapeutic use , Horse Diseases/drug therapy , Omeprazole/therapeutic use , Stomach Ulcer/veterinary , Administration, Oral , Age Factors , Animals , Animals, Newborn , Breeding , Double-Blind Method , Enzyme Inhibitors/administration & dosage , Female , Gastroscopy/veterinary , Horses , Housing, Animal , Male , Ointments , Omeprazole/administration & dosage , Severity of Illness Index , Stomach Ulcer/drug therapy , Treatment Outcome , United StatesABSTRACT
Equine gastric ulcer syndrome (EGUS) is very common among performance horses, with a reported prevalence of approximately 90% in racehorses, and also > 50% in foals. Omeprazole, an acid pump inhibitor 5 times more potent than ranitidine, has been used with great success to treat EGUS. This multicentre study of Thoroughbred racehorses with endoscopically verified gastric ulcers was designed to demonstrate the efficacy of an equine oral paste formulation of omeprazole in the treatment and prevention of recurrence of EGUS. Of the 100 horses entered into the study, 25 were sham-dosed for the full 58 days of the study. The remaining 75 horses all received omeprazole paste, 4 mg/kg bwt/day once daily for 28 days. At Day 28, 25 of treated horses continued on this dosing regimen while 25 received a half dose (2 mg/kg bwt once daily) and 25 horses were sham-dosed. By Day 28, gastric ulcers were completely healed in 77% of omeprazole-treated horses, while 92% were significantly (P < 0.01) improved. In contrast, 96% of the sham-dosed horses still had gastric ulcers at Day 28. The improvement was maintained in horses that continued on either a full dose or half dose of omeprazole paste until Day 58. However, in those horses that were removed from omeprazole treatment at Day 28, the incidence and severity of the gastric ulcers at the end of the study were similar to those horses that did not receive the omeprazole paste. This study demonstrates that omeprazole paste, 4 mg/kg bwt per os, once daily, is highly effective in healing gastric ulcers in Thoroughbred racehorses and that either a full dose or half dose of omeprazole paste effectively prevents the recurrence of EGUS. The study also indicates that gastric ulcers in untreated horses did not demonstrate a significant rate of spontaneous healing.
