Abstract: Background - Goats can develop abomasal ulceration due to inappetence, adverse reactions to medications, and stress. There is currently no FDA approved drug for prevention or treatment of abomasal ulceration in goats. Famotidine, a histamine type-2 (H-2) receptor antagonist is often used in veterinary medicine to treat gastric ulceration in dogs and in human medicine to treat duodenal ulceration. Objectives - The objectives of these studies were to determine the pharmacokinetics of a single dose of famotidine in goats via subcutaneous (SC) (1.2 mg/kg) and intravenous (IV) (0.6 mg/kg) administration. Animals - Six healthy goats were used in each study. Methods - Plasma samples were collected and analyzed using reverse phase high performance liquid chromatography (HPLC) for famotidine concentration. Results - Elimination half-life for IV was 0.31 hours while SC was 1.31 hours. Mean residence time for IV was estimated at 0.33 hours and for SC was estimated at 1.62 hours. Maximum plasma concentration for IV administration was 5476 ng/mL and for SC administration was 735 ng/mL. SC Bioavailability was calculated at 63%. Conclusions and Clinical Importance - Compared to other studies in horses and cattle, famotidine appears to be more rapidly eliminated in goats. However, comparing the two routes of administration, SC administration of famotidine may be a useful way of maintaining plasma concentration over time for goats. Future studies investigating pharmacodynamics, withdrawal period, and microbiome effects would be beneficial.
