What is Imodium?
Imodium (generically known as loperamide) is a synthetic opioid. All opioids (think morphine, oxycodone, etc.) have a well-earned reputation for causing constipation. Loperamide is so good at causing constipation that this “side effect” has become the primary reason we use it as a medication. 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.
How Does Imodium Treat Diarrhea In Dogs?
Imodium is actually a brand name for a drug called loperamide, a synthetic opiod. It works by slowing down movement in the intestines, which allows the walls of the intestines to absorb more electrolytes and water and stops food from being pushed through the intestines too quickly.
Slowing down intestinal movement helps your dog’s body digest properly and prevents diarrhea.
You should ask your veterinarian before giving your dog Imodium for diarrhea, though, as there are many situations where it can be harmful.
Dogs Who Are Experiencing Additional Health Problems
Imodium is not always safe for dogs suffering from other serious health problems, such as kidney disease, liver disease, Addison’s disease, inflammatory bowel disease, or hypothyroidism.
Additionally, you don’t want to give Imodium to dogs currently experiencing difficulty breathing or stomach pain, or those who have suffered a recent head wound.
Shelties, Australian shepherds, border collies, and other herding breeds often have a gene mutation (called MDR1) that makes it difficult for their bodies to process Imodium and a few other medications.
Not all individuals in this group have the gene, but the only way to know for sure is by having a genetic test performed (the good news is that you can have this test performed easily via a dog DNA test kit).
So, unless you know for sure that your herding dog does not have this gene mutation, avoid giving him Imodium.