2. Digestive Aids For dogs experiencing minor digestive issues, OTC medications like Pepcid AC (famotidine) and Kaopectate can be beneficial. Famotidine can help reduce stomach acid and alleviate symptoms of upset stomach, while Kaopectate can help with diarrhea. Again, correct dosing is vital, and it’s best to consult with your vet regarding the specific condition and appropriate treatment.