Hyoscyamine is a drug that slows down muscle contractions in the urinary bladder, stomach, and intestines. It can also decrease the amount of stomach acid produced and make the heart beat faster. Veterinarians may prescribe hyoscyamine to help reduce diarrhea or frequent loose stools in dogs with conditions like irritable bowel syndrome. Occasionally, it may be tried in dogs to treat some types of urinary incontinence or to treat slow heartbeats associated with some heart conditions. The FDA (U.S. Food & Drug Administration)
has approved this drug for use in humans but it is not officially approved for use in animals in the US. The FDA allows veterinarians to prescribe products containing this drug in different species or for other conditions in certain situations. You and your veterinarian can discuss why this drug is the most appropriate choice.