Success of treatment comparing two omeprazole preparations for Equine Gastric Ulcer Syndrome (EGUS)

Abstract

Equine Gastric Ulcer Syndrome (EGUS) is a common problem in equine athletes. The ECEIM consensus statement and the manufacturers recommend omeprazole at a dosage of 2 4 mg/kg PO SID (buffered formulations) or 1 2 mg/kg PO SID (enteric coated granules) for the treatment of ESGD (Equine Squamous Gastric Disease) and the same dosages in combination with sucralfate (12 mg/kg PO BID) for EGGD (Equine Glandular Gastric Disease). In this study, the two formulations were compared in an equine hospital setting. A modified clinical scoring was used to include 87 horses (January 2019-December 2020) presented for recurrent colic, weight loss, exercise insufficiency or typical behavior (bruxism, groaning), in which gastroscopy was performed. Horses were classified as 0 4 for ESGD (consensus statement) and 0 3 for EGGD (modified from non-remarkable/mild/moderate/severe findings according to the Consensus statement) by the veterinarian performing the gastroscopy and led to the recommendation of therapy in 63 cases. Omeprazole therapy (buffered formulation 4 mg/kg PO SID, GastroGard , Boehringer Ingelheim or enteric coated granules 2 mg/kg PO SID, Equizol , CP Pharma), in case of EGGD combined with sucralfate (12 mg/kg PO BID, Sucrabest , Combustin) was recommended in combination with improvements concerning housing, feeding and reduction of stress according to the ECEIM consensus statement. Gastroscopy was repeated about 4 weeks later in 23 horses. Standing images were randomized and scored twice by two blinded, experienced observers (ECEIM diplomats), so that 4 scorings for both time-points were available of ESGD and EGGD. The mean values of these scorings were the basis for the evaluation of treatment success. Additionally, inter-and intra-observer agreement were compared for ESGD and EGGD. Both formulations were highly effective in improving ESGD by ≤ 2 subgrades or by achieving grade 0 in 93 % and 100 % of horses treated with buffered (n = 15 GastroGard ) and encapsulated formulations (n = 8, Equizol ), respectively. EGGD was improved by ≤ 1 subgrade or achieving grade 0 in 64 % and 71 % of horses treated with buffered and enteric coated formulations combined with sucralfate, respectively. No significant differences between the two formulations were found for either ESGD or EGGD (P > 0.999). Inter-and intra-observer-Agreement were excellent for ESGD (κ = 0.832 0.975), while the inter-observer agreement for EGGD was found to be fair (κ = 0,390). In conclusion, both omeprazole formulations can be recommended for the treatment of EGUS, in particular ESGD. Differences in long-Term effect and recurrence rates should be studied in future studies.