Abomasal ulcers are a challenge in animal farming, affecting health, welfare, and productivity. Omeprazole's (OPZ) efficacy in treating these ulcers is known, but data on its pharmacokinetics (PK) in adult goats and sheep are lacking. The purpose of this research was to investigate and contrast OPZ's PK in these animals following a single intravenous (IV, 1 mg/kg) and subcutaneous (SC, 2 mg/kg) doses. Sheep and goats had similar exposure levels for all administration routes, with no significant AUC_(0-∞)D variations. Half-life was short in both species (sheep: 0.20 h; goats: 0.31 h). Goats had a higher volume of distribution after IV administration. Clearance was rapid, and extraction ratio values were high for both goats and sheep (43% and 30%, respectively). SC administration showed similarities in C_max and T_max values between species. Both goats and sheep had high bioavailability (about 80%) levels and comparable mean absorption times (MAT). Despite some PK parameters' variances, systemic exposure to OPZ is similar in sheep and goats. SC administration's high bioavailability suggests it as a convenient field application route. Further investigations are needed to understand OPZ's effectiveness in small ruminants with abomasal ulcers and improve dosing regimens for clinical use.