On the other hand, Imodium is not very good at relieving pain, at least at safe dosage levels, so it is never legitimately used for this reason. Is Imodium Safe for Dogs? Some dogs with certain types of diarrhea can take Imodium, but in other cases, giving your dog Immodium can lead to potentially serious side effects like constipation, sedation (which can be severe), bloat and pancreatitis.