Omeprazole is a proton pump inhibitor commonly used in horses to manage gastric acid-related conditions, such as gastric ulcers. It functions by reducing the production of gastric acid in the stomach, thereby aiding in the healing of existing ulcers and prevention of new ulcer formation. Omeprazole is frequently administered to horses that are at risk of developing gastric ulcers due to stress, intensive training, or other physiological factors. The pharmacokinetics, efficacy, and safety of omeprazole in equine patients have been the subject of numerous studies. This page compiles peer-reviewed research studies and scholarly articles that explore the pharmacological properties, therapeutic applications, and clinical outcomes associated with omeprazole use in horses.
Sanchez LC, Giguère S, Javsicas LH, Bier J, Walrond CJ, Womble AY.Gastric tonometry is commonly used in humans as an assessment of intestinal mucosal perfusion. Values in healthy foals are currently unknown. Objective: Age, enteral feeding, and omeprazole administration would significantly alter gastric tonometry measurements in neonatal foals. Methods: Nine clinically normal foals were used to assess the effect of age and feeding, and 8 similar foals were used to assess the effect of omeprazole. Methods: At 1, 7, and 14 days of age, gastric intramucosal PCO2 (PgCO2) and arterial blood gas samples were obtained at baseline, immediately after feeding milk, an...
McKeever JM, McKeever KH, Albeirci JM, Gordon ME, Manso Filho HC.A large percentage of performance horses develop gastric ulcers and many of those horses are treated with omeprazole. Unfortunately, no data have been published on the effects of the drug on markers of performance in animals without ulcers. Objective: Omeprazole would alter markers of aerobic and anaerobic performance. Methods: Ten unfit, healthy, ulcer free, Standardbred mares were administered either control (CON; oral apple sauce, 20 ml) or omeprazole (OP; oral paste, 4 mg/kg bwt s.i.d.) in a random crossover fashion with the investigators blind to the treatment. Treatments were administere...
Bell RJ, Mogg TD, Kingston JK.In recent years, gastric ulceration has been recognised as a common, possibly performance-limiting disease of adult horses. Here, we aim to provide the reader with a useful review of recent literature covering all aspects of equine gastric ulcer syndrome (EGUS) in adult horses. The anatomy and physiology of the stomach, with particular reference to secretion of acid and mucosal protective mechanisms, are reviewed, as are the differing theories relating to the aetiopathogenesis of gastric ulceration. We also explore the possible influence of various management factors on development of the dise...
Bell RJ, Mogg TD, Kingston JK.In recent years, gastric ulceration has been recognised as a common, possibly performance-limiting disease of adult horses. Here, we aim to provide the reader with a useful review of recent literature covering all aspects of equine gastric ulcer syndrome (EGUS) in adult horses. The anatomy and physiology of the stomach, with particular reference to secretion of acid and mucosal protective mechanisms, are reviewed, as are the differing theories relating to the aetiopathogenesis of gastric ulceration. We also explore the possible influence of various management factors on development of the dise...
Andrews FM, Frank N, Sommardahl CS, Buchanan BR, Elliott SB, Allen VA.The study was performed to evaluate the efficacy of omeprazole powder in sterile water, administered intravenously, on gastric juice pH in adult horses with naturally occurring gastric ulcers. Omeprazole (0.5 mg/kg, IV) was administered once daily for 5 days to 6 adult horses with gastric ulcers. Gastric juice was aspirated through the biopsy channel of an endoscope and pH was measured before and 1 hour after administration of omeprazole on day 1, and then before and after administration of omeprazole on day 5. Gastric ulcer scores were recorded on day 1 before administration of omeprazole and...
Lester GD, Smith RL, Robertson ID.To compare the effects of oral administration of omeprazole and ranitidine on gastric squamous ulceration in Thoroughbreds in race training. Methods: Modified crossover study. Methods: 60 Thoroughbreds in race training with gastric squamous mucosal ulceration. Methods: Horses were randomly allocated into 3 groups. Group 1 received no treatment for 28 days followed by administration of omeprazole (4 mg/kg [1.8 mg/lb], PO, once daily) for 28 days; group 2 received omeprazole (4 mg/kg, PO, once daily) for 28 days followed by no treatment for 28 days; and group 3 received ranitidine (6.6 mg/kg [3....
McClure SR, White GW, Sifferman RL, Bernard W, Hughes FE, Holste JE, Fleishman C, Alva R, Cramer LG.To determine whether omeprazole oral paste administered at a dosage of 0.5 or 1 mg/kg (0.23 or 0.45 mg/lb), PO, every 24 hours would effectively prevent the recurrence of gastric ulcers in horses in race training. Methods: Prospective study. Methods: 135 horses. Methods: Horses with gastric ulcers were treated with omeprazole at a dosage of 4 mg/kg (1.8 mg/lb), PO, every 24 hours for 28 days. Horses in the dose selection portion of the study were sham dose treated or received 0.5 or 1 mg of omeprazole/kg, PO, every 24 hours for an additional 28 days. Horses in the dose confirmation portion of ...
Sanchez LC, Murray MJ, Merritt AM.To evaluate the efficacy of omeprazole paste, a commonly used antiulcer drug, on intragastric pH in clinically normal neonatal foals. Methods: 6 clinically normal foals between 5 and 14 days of age. Methods: Intragastric pH was recorded in each foal by use of a disposable antimony pH electrode with internal reference. Values for intragastric pH were recorded every 4 seconds by use of an ambulatory pH monitor. There were two 24-hour recordings of intragastric pH for each foal, with 24 hours between recordings. Foals were not administered any drugs during the first recording. Foals were administ...
Merritt AM, Sanchez LC, Burrow JA, Church M, Ludzia S.Ulceration of the squamous gastric mucosa is commonly associated with intensive training programmes in horses, but only one compound ('Gastrogard') has been subjected to controlled scrutiny as to therapeutic efficacy. Objective: To compare the gastric acid inhibitory efficacy of one manufactured ('GastroGard') and 3 generic pharmacy-compounded preparations of the proton pump inhibitor omeprazole (OME) in the mature horse. Objective: All OME preparations tested would induce a clinically acceptable effect. Methods: Six healthy mature gastrically cannulated horses of various breeds, 3 mares and 3...
Doucet MY, Vrins AA, Dionne R, Alva R, Ericsson G.The efficacy of a paste formulation of the H+, K+, -ATPase inhibitor omeprazole was evaluated in standardbred racehorses for the treatment and prevention of gastric ulcers. Twenty standardbred racehorses in training, aged 2 to 9 years, were enrolled from 2 training centres in this field trial. Endoscopic examinations confirmed the presence of gastric ulcers in all horses, prior to allocation and treatment and on day 0. Lesions were scored on a scale of 0 to 3 (intact epithelium to extensive ulceration). Replicates were formed, based on training level and location. Within replicates, 1 horse wa...
Nieto JE, Spier S, Pipers FS, Stanley S, Aleman MR, Smith DC, Snyder JR.To compare effects of a commercially available omeprazole paste and a compounded omeprazole suspension on healing of gastric ulcers in Thoroughbred racehorses in active training. Methods: Randomized controlled trial. Methods: 32 horses with gastric ulcers. Methods: Horses were assigned to 2 groups on the basis of endoscopic gastric ulcer severity. Group-1 horses were treated with omeprazole suspension for 30 days and with omeprazole paste for an additional 30 days. Group-2 horses were treated with omeprazole paste for 30 days and omeprazole suspension for an additional 30 days. Serum omeprazol...
Kollias-Baker C, Cox K, Jones J.Omeprazole is a proton-pump inhibitor recently approved in the United States for the treatment of gastric ulcer disease in horses. A study was designed to determine the effects of omeprazole treatment on the physiological indices of performance of horses during incremental treadmill exercise. In a crossover-design study carried out over 2 weeks, five horses completed standardized incremental exercise tests on a high-speed treadmill either with no treatment or treatment with omeprazole. No statistically significant effects of omeprazole were found on the mean maximum responses for specific oxyg...
Murray MJ, Eichorn ES, Holste JE, Cox JL, Stanier WB, Cooper WL, Cooper VA.A paste formulation of the H+,K(+)-ATPase inhibitor omeprazole was evaluated in Thoroughbred foals and yearlings for its safety and acceptability. Twenty foals age 11-16 weeks and 20 yearling horses age 15-17 months were included and gastroscopic examinations performed 1-3 days before and at the end of each trial. Lesions were scored on a scale of 0 to 3 and animals allocated based on endoscopic lesion score and sex, with 4 animals in each of 5 replicates. Dosages of 4 mg omeprazole/kg bwt or sham treatment were administered once daily for 28 days, from a syringe graduated in 50 lb (22.68 kg) ...
Vatistas NJ, Snyder JR, Nieto J, Thompson D, Pollmeier M, Holste J.Gastric ulceration has been found to occur in 80-90% of Thoroughbreds in active race training. Previously, variable success has been reported using mucosal surface protectants and H2 receptor antagonist. Omeprazole, a substituted benzimidazole, has been shown to inhibit gastric acid secretion in both man and animals. Fourteen horses, in active race training and with endoscopic evidence of moderated to severe gastric ulceration were divided into 2 groups: Group 1 (7 horses) were given placebo paste orally once daily for 28 days; Group 2 (7 horses) received 1.54 g active omeprazole in the placeb...
Plue RE, Wall HG, Daurio C, Attebery DK, Cox JL, Wallace DH.Omeprazole has been shown to promote healing of spontaneously occurring gastric ulcers in horses when administered for 28 days at a dose of 4 mg/kg bwt/day and to prevent recurrence of ulcers in almost all horses when treatment is continued at a dose of at least 2 mg/kg bwt/day. The purpose of the 3 studies reported here was to 1) evaluate the evolution of potential effects of omeprazole paste (GastroGard), at a dose of 20 mg/kg bwt/day (5x the recommended dose) for 91 days in mature Thoroughbred horses; 2) evaluate the safety in young horses of omeprazole paste when dosed at 4 mg/kg bwt/day (...
MacAllister CG, Sifferman RL, McClure SR, White GW, Vatistas NJ, Holste JE, Ericcson GF, Cox JL.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 ...
Daurio CP, Holste JE, Andrews FM, Merritt AM, Blackford JT, Dolz F, Thompson DR.In a multicentre trial, 13 cannulated horses were treated orally once daily with a paste that delivered omeprazole at a dose of 4 and 5 mg/kg bwt in a 2-period crossover design to evaluate steady state gastric acid suppression. In each period, basal (unstimulated) and pentagastrin-stimulated gastric output were evaluated at 5-8 h after 5 doses, at 13-16 h after 10 doses, and at 21-24 h after 15 doses. Baseline data for gastric acid secretion were collected once for each horse in the month prior to initiation of omeprazole treatment. The inhibition of gastric acid secretion relative to baseline...
Haven ML, Dave K, Burrow JA, Merritt AM, Harris D, Zhang D, Hickey GJ.The antisecretory activity of omeprazole on gastric acid when administered i.v., intragastrically or per os, was evaluated in 2 female and 3 castrated male horses. Each horse had been prepared with a chronic indwelling gastric cannula. A single i.v. administration of omeprazole (1.5 mg/kg bwt) was effective in abolishing basal and pentagastrin (PG)-stimulated acid secretion. Once daily, nasogastric administration of omeprazole in acid-stable granules for 5 days inhibited acid secretion in a dose-dependent manner: 57% (1.5 mg/kg bwt) and 98% (5.0 mg/kg bwt) reduction of PG-stimulated acid secre...
Sandin A, Andrews FM, Nadeau JA, Doherty TJ, Nilsson G.The effect of intramuscular (i.m.) omeprazole (0.25 or 1.0 mg/kg bwt; LD and HD), respectively, on volume, total acid output (TAO) and pH of the gastric juice was studied during 24 h in 5 horses with a chronically implanted gastric cannula. Whether secretion in controls was basal or stimulated with pentagastrin (8 micrograms/kg bwt/h), volume (NS) and TAO (P < 0.01, NS) gradually decreased and pH increased (P < 0.05, NS). Omeprazole significantly reduced the average basal TAO by 49 +/- 6% (LD) and 88 +/- 3% (HD) and the stimulated TAO by 64 +/- 2% and 97 +/- 1%. Basal pH in controls was 2.1-4....
Andrews FM, Doherty TJ, Blackford JT, Nadeau JA, Saxton AM.To determine the effects of orally administered omeprazole, as enteric-coated capsules, on baseline and stimulated gastric acid secretion in horses. Methods: 5 healthy 8-year-old mixed-breed horses fitted with gastric cannulas. Methods: Enteric-coated granules of omeprazole were mixed with corn syrup and administered orally once daily for 5 consecutive days. On days 1 and 5 beginning 5 hours after omeprazole administration, 4 gastric fluid samples were collected, each for 15 minutes, via the gastric cannula (baseline samples). Pentagastrin was administered IV as a constant infusion for the sub...
Murray MJ, Haven ML, Eichorn ES, Zhang D, Eagleson J, Hickey GJ.Seventeen Thoroughbred horses with moderate to severe gastric ulceration were purchased from a race track within 10 days of racing and were treated once daily with either omeprazole (9 horses) or vehicle (8 horses) and evaluated gastroscopically for ulcer healing. Horses were administered omeprazole (1.5 mg/kg bwt/day) or vehicle by nasogastric tube once daily. Gastroscopic examination was performed on Days 0, 4, 7, 11, 14, 17, 21, 24 and 28, until lesions healed completely. Selected images of gastric lesions were captured by computer at each endoscopic examination, with a measuring caliper in...
Baker SJ, Gerring EL.We investigated the effects of a range of IV administered doses of omeprazole (0.125 to 2.0 mg/kg of body weight) on gastric pH (monitored by indwelling electrode) and plasma gastrin concentration, compared with those of IV administered ranitidine (1.0 mg/kg) in 4 Welsh mountain-type ponies. Pharmacokinetic variables of IV administered omeprazole also were examined. Episodes of high gastric pH in the basal state obscured the effect of acid suppression on intragastric pH; however, omeprazole induced dose-dependent increase in mean gastric pH (P < 0.01) during the 11 hours after its administr...
Sangiah S, MacAllister CC, Amouzadeh HR.The basal gastric pH and free acid contents from five young adult healthy horses were determined at one hour intervals for eight hours. The basal gastric pH and free acid contents varied from 1.63 +/- 0.06 to 1.97 +/- 0.11 and 26.42 +/- 4.14 to 17.92 +/- 5.28 mmol litre-1, respectively. Misoprostol, a methylester analogue of prostaglandin (5 micrograms kg-1, orally) produced a time-dependent increase in the basal gastric pH to above 3.5 (P less than 0.05) at three, four and five hours after administration with a concomitant reduction of 80 to 90 per cent in the basal gastric free acid contents...
Mason LV, Moroney JR, Mason RJ.Guidelines regarding the impact and value of prophylaxis or maintenance therapy in equine gastric ulcer syndrome (EGUS) are not well-established or defined. The merits and the magnitude of effects of prophylaxis for spontaneous or recurrent squamous gastric ulceration in horses in training are uncertain. Objective: To pool data from randomised controlled trials (RCTs) to eliminate reporting bias and evaluate the efficacy of prophylactic omeprazole in the prevention of EGUS in training horses, and secondarily to compare prophylactic dosages of omeprazole. Methods: Meta-analysis. Methods: This m...
Wilson CS, Brookes VJ, Hughes KJ, Trope GD, Ip H, Gunn AJ.In human subjects, arytenoid chondritis can be caused by chemical trauma of mucosa attributable to gastro-oesophageal reflux. Although a similar process may be involved in the aetiopathogenesis of arytenoid chondritis in horses, the oesophageal lumen pH in this species is poorly understood. Objective: To determine if gastro-oesophageal reflux occurs in horses by characterising oesophageal lumen pH. Methods: Blinded, randomised, placebo-controlled, crossover, experimental study. Methods: Luminal oesophageal pH in six yearling horses was recorded over four 24 h periods using an ambulatory pH rec...
Birkmann K, Junge HK, Maischberger E, Wehrli Eser M, Schwarzwald CC.GastroGard, an omeprazole powder paste formulation, is considered the standard treatment for gastric ulcers in horses and is highly effective. Gastrozol, an enteric-coated omeprazole formulation for horses, has recently become available, but efficacy data are controversial and sparse. Objective: To investigate the efficacy of GastroGard and Gastrozol at labeled doses (4 and 1 mg of omeprazole per kg bwt, respectively, PO q24h) in healing of gastric ulcers. Methods: 40 horses; 9.5 ± 4.6 years; 491 ± 135 kg. Methods: Prospective, randomized, blinded study. Horses with an ulcer score ≥1 (Equi...
Ferlini Agne G, Somogyi AA, Sykes B, Knych H, Franklin S.In humans, omeprazole is metabolised by cytochrome P450 (CYP450) CYP2C19 and CYP3A4 with differences in CYP2C19 genotypes leading to variable response to therapy. Despite a wide use of omeprazole in horses with evidence of variable therapeutic efficiency, information regarding enzymatic metabolism is not currently available. This study aims to describe the in vitro kinetics of omeprazole metabolism and determine which enzyme(s) are responsible for omeprazole metabolism in horses. Omeprazole (0-800 uM) was incubated with liver microsomes and a panel of equine recombinant CYP450s (eq-rCYP). Meta...
Haven ML, Dave K, Burrow JA, Merritt AM, Harris D, Zhang D, Hickey GJ.The antisecretory activity of omeprazole on gastric acid when administered i.v., intragastrically or per os, was evaluated in 2 female and 3 castrated male horses. Each horse had been prepared with a chronic indwelling gastric cannula. A single i.v. administration of omeprazole (1.5 mg/kg bwt) was effective in abolishing basal and pentagastrin (PG)-stimulated acid secretion. Once daily, nasogastric administration of omeprazole in acid-stable granules for 5 days inhibited acid secretion in a dose-dependent manner: 57% (1.5 mg/kg bwt) and 98% (5.0 mg/kg bwt) reduction of PG-stimulated acid secre...
Merritt AM, Sanchez LC, Burrow JA, Church M, Ludzia S.Ulceration of the squamous gastric mucosa is commonly associated with intensive training programmes in horses, but only one compound ('Gastrogard') has been subjected to controlled scrutiny as to therapeutic efficacy. Objective: To compare the gastric acid inhibitory efficacy of one manufactured ('GastroGard') and 3 generic pharmacy-compounded preparations of the proton pump inhibitor omeprazole (OME) in the mature horse. Objective: All OME preparations tested would induce a clinically acceptable effect. Methods: Six healthy mature gastrically cannulated horses of various breeds, 3 mares and 3...
Bishop RC, Kemper AM, Wilkins PA, McCoy AM.Equine gastric ulcer syndrome (EGUS) is a common and significant cause of morbidity in horses, with a range of clinical signs, including inappetence, colic and poor performance. Hospitalised horses are exposed to factors that may induce EGUS, including fasting and nonsteroidal anti-inflammatory drug (NSAID) administration, and may be at risk for development of squamous (ESGD) and glandular gastric disease (EGGD). Prophylactic anti-ulcer medication is often prescribed for these patients, but drug selection is complicated by different aetiology and response to treatment of ESGD and EGGD. Objecti...
Sandin A, Andrews FM, Nadeau JA, Doherty TJ, Nilsson G.The effect of intramuscular (i.m.) omeprazole (0.25 or 1.0 mg/kg bwt; LD and HD), respectively, on volume, total acid output (TAO) and pH of the gastric juice was studied during 24 h in 5 horses with a chronically implanted gastric cannula. Whether secretion in controls was basal or stimulated with pentagastrin (8 micrograms/kg bwt/h), volume (NS) and TAO (P < 0.01, NS) gradually decreased and pH increased (P < 0.05, NS). Omeprazole significantly reduced the average basal TAO by 49 +/- 6% (LD) and 88 +/- 3% (HD) and the stimulated TAO by 64 +/- 2% and 97 +/- 1%. Basal pH in controls was 2.1-4....
Bell RJ, Mogg TD, Kingston JK.In recent years, gastric ulceration has been recognised as a common, possibly performance-limiting disease of adult horses. Here, we aim to provide the reader with a useful review of recent literature covering all aspects of equine gastric ulcer syndrome (EGUS) in adult horses. The anatomy and physiology of the stomach, with particular reference to secretion of acid and mucosal protective mechanisms, are reviewed, as are the differing theories relating to the aetiopathogenesis of gastric ulceration. We also explore the possible influence of various management factors on development of the dise...
Sanchez LC, Giguère S, Javsicas LH, Bier J, Walrond CJ, Womble AY.Gastric tonometry is commonly used in humans as an assessment of intestinal mucosal perfusion. Values in healthy foals are currently unknown. Objective: Age, enteral feeding, and omeprazole administration would significantly alter gastric tonometry measurements in neonatal foals. Methods: Nine clinically normal foals were used to assess the effect of age and feeding, and 8 similar foals were used to assess the effect of omeprazole. Methods: At 1, 7, and 14 days of age, gastric intramucosal PCO2 (PgCO2) and arterial blood gas samples were obtained at baseline, immediately after feeding milk, an...
McKeever JM, McKeever KH, Albeirci JM, Gordon ME, Manso Filho HC.A large percentage of performance horses develop gastric ulcers and many of those horses are treated with omeprazole. Unfortunately, no data have been published on the effects of the drug on markers of performance in animals without ulcers. Objective: Omeprazole would alter markers of aerobic and anaerobic performance. Methods: Ten unfit, healthy, ulcer free, Standardbred mares were administered either control (CON; oral apple sauce, 20 ml) or omeprazole (OP; oral paste, 4 mg/kg bwt s.i.d.) in a random crossover fashion with the investigators blind to the treatment. Treatments were administere...
Nieto JE, Spier S, Pipers FS, Stanley S, Aleman MR, Smith DC, Snyder JR.To compare effects of a commercially available omeprazole paste and a compounded omeprazole suspension on healing of gastric ulcers in Thoroughbred racehorses in active training. Methods: Randomized controlled trial. Methods: 32 horses with gastric ulcers. Methods: Horses were assigned to 2 groups on the basis of endoscopic gastric ulcer severity. Group-1 horses were treated with omeprazole suspension for 30 days and with omeprazole paste for an additional 30 days. Group-2 horses were treated with omeprazole paste for 30 days and omeprazole suspension for an additional 30 days. Serum omeprazol...
Louie EW, Berryhill EH, Nieto J, Wensley F, Knych H, Finno CJ, Morgan JM.Gastric ulceration can be induced by athletic training and is a significant welfare concern. The objective of this study was to evaluate the effect of gastric ulcer induction on heart rate variability (HRV) in the horse. We hypothesized that induction of gastric ulcers would decrease HRV and increase low frequency fluctuations, consistent with increased sympathetic tone. A convenience sample of 8 horses in a larger study were enrolled. Horses were randomly assigned to receive water or 2 mg/kg omeprazole orally once daily for 28 days. Gastric ulcers were induced through intermittent feed withho...
Doucet MY, Vrins AA, Dionne R, Alva R, Ericsson G.The efficacy of a paste formulation of the H+, K+, -ATPase inhibitor omeprazole was evaluated in standardbred racehorses for the treatment and prevention of gastric ulcers. Twenty standardbred racehorses in training, aged 2 to 9 years, were enrolled from 2 training centres in this field trial. Endoscopic examinations confirmed the presence of gastric ulcers in all horses, prior to allocation and treatment and on day 0. Lesions were scored on a scale of 0 to 3 (intact epithelium to extensive ulceration). Replicates were formed, based on training level and location. Within replicates, 1 horse wa...
Andrews FM, Doherty TJ, Blackford JT, Nadeau JA, Saxton AM.To determine the effects of orally administered omeprazole, as enteric-coated capsules, on baseline and stimulated gastric acid secretion in horses. Methods: 5 healthy 8-year-old mixed-breed horses fitted with gastric cannulas. Methods: Enteric-coated granules of omeprazole were mixed with corn syrup and administered orally once daily for 5 consecutive days. On days 1 and 5 beginning 5 hours after omeprazole administration, 4 gastric fluid samples were collected, each for 15 minutes, via the gastric cannula (baseline samples). Pentagastrin was administered IV as a constant infusion for the sub...
Murray MJ, Haven ML, Eichorn ES, Zhang D, Eagleson J, Hickey GJ.Seventeen Thoroughbred horses with moderate to severe gastric ulceration were purchased from a race track within 10 days of racing and were treated once daily with either omeprazole (9 horses) or vehicle (8 horses) and evaluated gastroscopically for ulcer healing. Horses were administered omeprazole (1.5 mg/kg bwt/day) or vehicle by nasogastric tube once daily. Gastroscopic examination was performed on Days 0, 4, 7, 11, 14, 17, 21, 24 and 28, until lesions healed completely. Selected images of gastric lesions were captured by computer at each endoscopic examination, with a measuring caliper in...
Pagan JD, Petroski-Rose L, Mann A, Hauss A.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 fe...
Li Z, Du S, Wang X, Zhang L, Liu X, Fan Q, Yang H, Gao R.Phenylbutazone (PBZ) is the most commonly used drug to treat symptoms of lameness in horses; however, it is associated with adverse effects such as gastric ulcer syndrome (EGUS). Interestingly, many practitioners prescribe omeprazole (OME) concurrently with PBZ to prevent the development of EGUS. However, the efficacy and safety of this practice in Mongolian horses with chronic lameness remain unknown. Objective: To evaluate the clinical effects of a combination of PBZ and OME on chronic lameness in Mongolian horses. Methods: Randomised block experimental design. Methods: Eighteen Mongolian ho...
Huxford KE, Dart AJ, Perkins NR, Bell R, Jeffcott LB.AIMS To compare the efficacy of an enteric coated esomeprazole paste with an enteric coated omeprazole paste to increase gastric pH after oral administration in horses. METHODS Nine adult Standardbred horses were randomly assigned to three groups, each containing three horses, for a study comprising three phases of 10 days, with an 18-day washout period between each phase. In each phase, three horses received either 0.5 mg/kg esomeprazole, 1 mg/kg omeprazole or a placebo, as an oral paste, once daily for 10 days (Days 0-9). Over the course of study all horses received all three treatments....
Sundra T, Gough S, Rossi G, Kelty E, Rendle D.Oral omeprazole is the accepted treatment for equine squamous gastric disease (ESGD); however, it is not universally effective. Esomeprazole results in more consistent and pronounced acid suppression in men and is more effective than omeprazole in the treatment of oesophageal and gastric disease. Pharmacodynamic and pilot clinical studies have indicated esomeprazole might also be more effective than omeprazole in horses. Objective: To compare the efficacy and safety of oral esomeprazole and omeprazole pastes in the treatment of ESGD and, where present, concurrent equine glandular gastric disea...
Williams Louie E, Nieto J, Wensley F, Morgan JM, Finno CJ, Berryhill EH.Omega-3 fatty acid and alpha-tocopherol supplementation reduces gastric ulcer formation in humans and rodents; however, efficacy of prevention in horses is unknown. Equine Omega Complete (EOC) is an oral supplement containing omega-3 fatty acids and alpha-tocopherol. Objective: Determine if EOC supplementation prevents gastric ulcers and increases serum alpha-tocopherol concentrations in healthy horses. Methods: Nine thoroughbred geldings; 5-13 years old. Methods: Prospective randomized block design, repeated in crossover model. Horses were administered EOC, omeprazole, or water PO for 28 ...
Shan R, Steel CM, Sykes B.The impact of recommended withholding periods (RWPs) for omeprazole on the recurrence of Equine Gastric Ulcer Syndrome (EGUS) is unknown. The study was designed to compare the effect of two RWPs on EGUS recurrence post-omeprazole treatment and to determine if a nutraceutical supplement would reduce EGUS recurrence when administrated during an RWP. The study was a blinded, randomized clinical trial. Part 1: Horses were allocated to an RWP0 or RWP2 and crossed over after 4-weeks. Horses received oral omeprazole once daily, except during the RWPs at the end of the treatment periods. Part 2: Horse...
Menzies-Gow NJ, Shurlock T.Feedstuffs are often recommended to mitigate potential damage from acid associated with equine squamous gastric disease (ESGD). In acidic conditions, pectin alters its structure to one like mucus and binds the stomach mucosa, whilst alfalfa has a strong intrinsic acid buffering capacity. The study aimed to determine whether feeding a commercial beet pulp/alfalfa/oat fibre mix aids ESGD healing and/or prevention of recurrence. Ten adult horses with naturally occurring ESGD were included. All animals were treated with omeprazole as per the attending veterinarian's recommendation and randomly all...
Neville E, Pigott J.To describe the clinical presentation of a Thoroughbred filly with acute hemoperitoneum from a splenic source immediately after racing. Methods: A 3-year-old Thoroughbred filly used for racing and that had raced shortly before presentation to the hospital. Unassigned: On presentation, the filly was quiet, alert, and responsive with a heart rate of 76 beats/min, pale mucous membranes, and absent borborygmi. All other physical examination parameters were within normal limits. Abdominal ultrasound was performed and revealed echogenic free abdominal fluid and a splenic hematoma. Abdominocentesis y...
