A study investigating the treatment of equine squamous gastric disease with long-acting injectable or oral omeprazole

Five- versus seven-day dosing intervals of extended-release injectable omeprazole in the treatment of equine squamous and glandular gastric disease

BACKGROUND

An extended-release injectable omeprazole formulation (ERIO) has become a popular treatment for equine squamous gastric disease (ESGD) and equine glandular gastric disease (EGGD) where it is available; however, published data are limited and optimal treatment regimens have not been determined.

OBJECTIVES

To compare effects of treatment on ESGD and EGGD when an ERIO formulation is administered at either 5- or 7-day intervals.

STUDY DESIGN

Retrospective clinical study.

METHODS

Case records and gastroscopy images of horses with ESGD or EGGD treated with ERIO were reviewed. Images were anonymised and graded by one researcher masked to treatment group. Treatment responses were compared between the two treatment schedules using univariable ordered logistic regression.

RESULTS

Forty-three horses were treated with ERIO at 5-day intervals and 39 horses at 7-day intervals. Signalment and presenting signs did not differ between groups. The proportions of horses with EGGD healing (to grade 0 or 1) in association with ERIO used at 5-day intervals (93%) were higher than associated with treatment at 7-day intervals (69%; odds ratio [OR]: 2.41, 95% CI: 1.23-4.74, p = 0.01). For ESGD, there was no significant difference in the proportion of horses healing in association with treatment at 5-day intervals (97%) compared with 7-day intervals (82%; OR: 2.75, 95% CI: 0.91-8.31, p = 0.07). Four of 328 injections were associated with an injection-site reaction (1%).

MAIN LIMITATIONS

Retrospective study design, lack of randomisation and limited case numbers.

CONCLUSIONS

The use of ERIO at 5-day intervals might be more appropriate than the 7-day interval that is used currently.

Comparison of oral esomeprazole and oral omeprazole in the treatment of equine squamous gastric disease

BACKGROUND

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.

OBJECTIVES

To compare the efficacy and safety of oral esomeprazole and omeprazole pastes in the treatment of ESGD and, where present, concurrent equine glandular gastric disease (EGGD).

STUDY DESIGN

Randomised, single-blinded controlled trial.

METHODS

Horses presenting with grade ≥2 ESGD lesions were randomly allocated to receive 4 mg/kg of either a buffered esomeprazole or omeprazole paste orally once daily for 28 days before gastroscopy being repeated within a further 3 days. Videos and images were anonymised and subsequently graded blind by one researcher. The severity of ESGD (and EGGD) lesions before and after treatment, and thereby treatment responses, were compared using univariable logistic regression.

RESULTS

A higher proportion of horses had ESGD healing in response to esomeprazole treatment (63/74, 85%) than with omeprazole treatment (43/73, 59%) (odds ratio [OR]: 4.00, 95% confidence interval [CI]: 1.81, 8.82, p = 0.001). In a subset of horses that had concurrent EGGD, a greater proportion of the horses treated with esomeprazole had lesions ≤grade 1 (esomeprazole 28/51, 55%; omeprazole 6/24, 25%; OR: 3.65, 95% CI: 1.25, 10.71, p = 0.02) Using grade 0 as the benchmark for EGGD healing, the difference remained significant (OR: 4.44, 95% CI: 1.33, 14.85, p = 0.02).

MAIN LIMITATIONS

It may not be possible to extrapolate these results to other populations with different signalment or management.

CONCLUSIONS

Oral-buffered esomeprazole was a more effective treatment for ESGD (and concurrent EGGD) than oral-buffered omeprazole.

A Comparison of the Efficacy of Two Omeprazole Formulations in the Treatment of Equine Gastric Ulcer Syndrome in Racehorses: A Blinded, Randomized Clinical Trial

Equine gastric ulcer syndrome (EGUS) is the most common disease of the stomach in horses and treatment is based on the oral administration of omeprazole for at least 28 days. Aim of this study was to compare the efficacy of two formulations of oral omeprazole-powder paste and gastro-enteric resistant granules-in the treatment of naturally occurring gastric ulcers in racehorses. Thirty-two adult racehorses, aged between 2 and 10 years old, with clinical signs of EGUS were included in this blinded, randomized clinical trial. Two gastroscopies were performed to evaluate gastric lesions in the squamous or glandular mucosa before and after 28 days of treatment. After the first gastroscopy, 2/32 horses were excluded because affected by equine squamous gastric disease (ESGD) 1/4. The remaining horses were divided into 4 groups, and were treated with 2 formulations of omeprazole (gastroenteric resistant granules, group 1, or powder paste, group 3) or with 2 placebo formulations (granules, group 2, or paste, group 4). Treatments were performed in the placebo horses affected by ESGD or equine glandular gastric disease after the T28 gastroscopy control. No differences were found between groups at T0. Differences were found between T0 vs. T28 for granular (P = .002) and powder paste (P = .01) formulations. No differences were detected between the two groups receiving omeprazole formulations at T28 (0.34) and between T0 vs. T28 for either of the groups receiving placebo treatments. For all the variables, the size of the effect was greater than 0.5, proving that the treatments had a considerable effect. Gastro-enteric resistant granules and powder paste omeprazole showed similar efficacy in the treatment of ESGD. The glandular mucosa responded poorly to treatment with omeprazole.

Testing and Refining the Ethical Framework for the Use of Horses in Sport

In 2021, in response to an acknowledged need for universal, consistent ethics to guide decision making in the horse sport sector, Campbell published a theoretical ethical framework for the use of horses in competitive sport. The research reported here tested the applied usefulness of that theoretical ethical framework through stakeholder engagement in a three-round modified Delphi study and refined it to develop a practical decision-making tool which can be applied consistently across multiple equestrian disciplines. Stakeholders from a broad range of equestrian competitive disciplines participated in the research. Participants were required to apply the ethical framework to a pre-determined ethical dilemma, individually (Rounds 1 and 2) and within a group (Round 3), and at the end of each round to complete a questionnaire designed to gauge opinion and user experience. At the completion of each round of testing, the theoretical framework was refined based on stakeholder feedback. Results showed that participants perceived useability and application of the framework to generally increase with each round. Qualitative content analysis identified key concepts, including cognition (e.g., broadens/deepens thinking) and application (e.g., considers multiple angles from a variety of information sources, needs to be a short/simple process). Results suggested that the refined framework is beneficial for group decision making across a wide variety of ethical issues and equestrian competitive disciplines. The framework thus has the potential to improve equine welfare through facilitating consistent ethical decision making in which the interests of the horse are prioritized.

Current Topics in Medical Colic

The list of medical causes of acute or chronic colic in horses is extensive. The purpose of this article is to review 4 medical causes of equine colic with a focus on newer trends in treatment. The 4 topics selected include gastric impaction, gastric glandular disease, colon displacement, and inflammatory bowel disease.

Evaluation of a long-acting injectable formulation of omeprazole in healthy dogs

BACKGROUND

To evaluate the efficacy of a single intramuscular adminsitration of long-acting omeprazole (LA-OMEP) in increasing gastric pH in dogs.

HYPOTHESIS

We hypothesized that LA-OMEP would meet in healthy dogs the clinical goals defined for human patients for treatment of gastroduodenal ulceration.

ANIMALS

Nine healthy research dogs.

METHODS

Prospective experimental study. Dogs were given a 4 mg/kg intramuscular injection of LA-OMEP. Intragastric pH was continuously recorded on treatment days 0 to 7. Daily mean pH and mean percentage time (MPT) intragastric pH was ≥3 or ≥4 were determined.

RESULTS

The mean onset of action for the LA-OMEP was 98.11 min (SD 46.39). The mean number of days the dogs' pH met established goals for MPT pH ≥3 was 5.5 days (range, 3-7) and 5.25 days for MPT pH ≥4 (range, 3-7). Long-acting omeprazole met the human clinical goals pH ≥3 for 72 hours in 8/8 of the dogs and MPT pH ≥4 for 96 hours in 7/8 of dogs.

CONCLUSIONS AND CLINICAL IMPORTANCE

The LA-OMEP formulation produced gastric acid suppression in healthy dogs for an average of 5 days and up to 7 days, after a single intramuscular injection. No major adverse effects were observed.

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.

A study investigating the treatment of equine squamous gastric disease with long-acting injectable or oral omeprazole

BACKGROUND

Equine squamous gastric disease (ESGD) is a highly prevalent disease in horses, particularly in elite athletes. Some horses respond slowly, or fail to respond, to the licensed treatment, oral omeprazole (ORLO).

OBJECTIVES

To compare rates of ESGD healing and improvement between ORLO and a long-acting injectable omeprazole preparation (LAIO).

STUDY DESIGN

Retrospective clinical study.

METHODS

The case records and gastroscopy images of horses presenting to Rainbow Equine Hospital over a 12-month period were reviewed, with images being reviewed blind by one of the authors (David Rendle). Treatment responses were compared between horses that received 2 or 4 injections of 4 mg/kg LAIO at weekly intervals, and horses that received ORLO at 4 mg/kg PO SID for 4 weeks. Data were compared using a Mann-Whitney test with post hoc Dunn's test, chi-squared test or Fisher's exact test.

RESULTS

Fifty-six horses met the inclusion criteria: 29 received LAIO and 27 received ORLO. Treatment groups were comparable in terms of signalment and ESGD lesions. There was a difference in rate of healing when LAIO and ORLO treatment groups were compared at 28 days (LAIO-97%; ORLO-67%; p = .005; OR = 14(1.8-158)), but no difference between LAIO at 14 days and ORLO at 28 days (LAIO-86%; ORLO-67%; p = .12; OR = 3.1 (0.9-10)). Five localised and self-limiting injection site reactions were identified in 3 horses out of 98 injections (5.1%).

MAIN LIMITATIONS

The study was limited by its retrospective nature, absence of randomisation and limited numbers.

CONCLUSIONS

Four weeks of treatment with LAIO resulted in better rates of ESGD healing than 4 weeks of ORLO. Larger more robust studies of LAIO are warranted.