Stomach diseases have an important place in the clinical pathology of dogs. Etiological factors can be nutritive, chemical, or infective, but treatment implies certain common general principles and a certain number of therapy protocols which are most often used. On the other hand, a part of the medicines used in the pharmacotherapy of stomach diseases in dogs are taken from the palette of medicines intended for human use, so that a regular dosage and regime of implementation are the main precondition for the success of the applied therapy. Drugs used in the treatment of stomach diseases include antiemetics, prokinetics, antacids, mucoprotectives, anticholinergics, H2-antagonists, proton pump inhibitors, semisynthetic derivatives of prostaglandin E1, and others. The therapy of stomach diseases implies the simultaneous application of several drugs from different pharmacodynamic groups (for instance, an antiemetic, a prokinetic, an antacid, and an Hg antagonist or a proton pump inhibitor) when it is necessary to establish a correct regime of implementation because of possible interaction, which will also be discussed in this work.