What Is a Safe Imodium Dosage for Dogs?

Woman holding a red pill up to a dog as he sniffs it

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Imodium is an over-the-counter medication that treats diarrhea in people. It can also be found under the names Diamode or its generic drug name, Loperamide. In dogs, it's used 'off label' or 'extra label' for the management of diarrhea. The terms 'off label' and 'extra label' refer to the fact that a medication, such as Imodium, is commonly used in a certain species for a certain reason but the FDA has not yet approved the medication for that species or reason.

There are several human OTC medications that are used off label on dogs, like Benadryl (diphenhydramine), Zyrtec (cetirizine), and Pepcid (famotidine). So while Imodium can be safe to give your dog, there are things you should consider before giving it to them. Certain drugs and medical conditions can interact with Imodium and it can be tricky to dose smaller breeds dogs, so always check with your veterinarian before giving your dog Imodium.

What Can Imodium Treat in My Dog?

Just like in people, Imodium is used primarily in dogs to treat diarrhea, but it may also prove beneficial for other gastrointestinal issues such as irritable bowel syndrome and acute colitis. Dogs can have diarrhea for a multitude of reasons, though, and not all of them should be treated with Imodium. So make sure to check with your vet whether your dog's diarrhea would be responsive to Imodium or not before starting.

How Much Imodium Should I Give My Dog?

Imodium is readily available in 2 mg tablets. The tablets would be most practical for medium dogs and larger, while the oral liquid is best utilized in small breed dogs. The usual dosage is 2 mg per 40 lbs of body weight (this equals 0.05 mg per lb). So a 40 lb dog would receive 1 full tablet, a 20 lb dog would receive half of a tablet, and a 10 lb dog would receive a quarter of a tablet. If your dog is less than 10 lbs, you may find it difficult to split a tablet small enough for them. Imodium is also readily available as an oral liquid at a concentration of 1 mg per 7.5 mL. At this concentration, the dosage would be about 0.4 mL per 1 lb of body weight. Some of the flavorings and additives that are used to make oral liquid medications more palatable for people may not be safe for dogs, so always check the list of inactive ingredients and consult your veterinarian before giving to your dog.

To administer the medication, simply wrap the tablet in a small piece of high value food, such as a pill pocket, chicken, bread, etc. Use just enough to adequately hide the pill to prevent any more GI indiscretion. The oral liquid is most easily measured out and administered with a syringe with measurements on it.

Side Effects With Imodium in Dogs

If you give your dog Imodium, they may experience flatulence, constipation, and even sedation as a side effect. Dogs that have a mutation on their MDR1 gene may experience profound sedation while on Imodium. Breeds that are susceptible to this gene mutation include collies, Australian shepherd, silken windhounds, Shetland sheepdogs, and German Shepherds. Your veterinarian can speak to your more about the MDR1 mutation and what it can mean for your dog.

If your dog were accidentally overdosed with Imodium they may be very sedate but you may also see loss of appetite, excessive salivating, cold body temperature, and a slow heart rate. If your dog has gotten into your supply of Imodium and you fear they may have overdosed, seek emergency veterinary care and call the ASPCA Animal Poison Control hotline at (888) 426-4435.

Other Considerations Before Giving Imodium

Imodium may not be safe for use in all dogs. If your dog has hypothyroidism, liver disease, kidney disease, Addison's disease (hypoadrenocorticism), or any other debilitation, speak to your vet before starting. It should also be used with caution in pregnant or nursing dogs. The use of Imodium in cats is more controversial and less accepted than in dogs, so it should be avoided.

Imodium can also interact with different medications. Commonly prescribed medications that can negatively interact with Imodium include erythromycin (a type of antibiotic) and ketoconazole (an anti-fungal). Be sure your vet knows about all other medications that your dog is taking, including vitamins, supplements, and herbal remedies, before you start Imodium.

Imodium can be a safe medication to use to treat your dog's diarrhea. If your dog's symptoms don't improve, or if you think your dog's diarrhea is from a toxin ingestion or an infection, call your vet to make an appointment to be seen.