商品名：Pepcid
Histamine2 antagonist (H2 blocker). Stimulation of acid secretion in the stomach requires activation of histamine type 2 receptors (H2 receptor), gastrin receptors, and muscarinic receptors. Famotidine and related H2 blockers inhibit the action of histamine on the histamine H2 receptor of parietal cells and inhibits gastric parietal cell gastric acid secretion. It increases stomach pH to help heal and prevent gastric and duodenal ulcers.
Famotidine, like other H2-receptor blockers, is used to treat ulcers and gastritis in a variety of animals. Although it is often used for animals with vomiting, there are no efficacy data to indicate that it is effective. There are no efficacy data to support its use for preventing nonsteroidal anti-inflammatory drug (NSAID)–induced bleeding and ulcers. Famotidine has been used by veterinarians as a preferred H2 blocker, but there is a lack of evidence to demonstrate superiority over other drugs in this class. Some studies have demonstrated efficacy at 1 mg/kg in dogs, while other studies have
劑量數字暫停提供：VetPro 的劑量改依 DRUGAPI 藥物資料庫對外的內容，DRUGAPI 目前不提供可直接計算的劑量。下方列出 DRUGAPI 的審查結論與劑量審查引用的來源；計算機可手動輸入劑量換算。
不得把犬貓胃內 pH 研究療程合併成通用計算器。須確認物種、真正酸相關適應症、途徑、精確單方／複方產品與規格、腎功能、期間／既往 H2RA 暴露、PPI 與 pH-dependent 共同用藥，以及療效／安全監測。所查公開資料未建立犬貓腎功能調整公式。
依出現頻率分組；嚴重副作用獨立列出，臨床上需立即辨識。
40-50%