Imodium for Dogs: Loperamide Dosage Calculator
Loperamide (Imodium A-D) slows the gut. The published veterinary range for dogs is 0.1–0.2 mg/kg every 8–12 hours, for no more than a day or two.
Enter your dog's weight to see the published reference range. Used for short-term, uncomplicated diarrhea.
How "mg per kg" dosing works
It is not safe for every dog: herding breeds with the MDR1 mutation can become dangerously sedated. Diarrhea caused by infection or toxins can also get worse when it is held in. Call your vet first.
Vets dose by body weight because the same amount of drug is spread through a bigger or smaller body. Drag the weight to see how the reference range and the number of tablets move together, and why a tablet sized for a 70 kg adult human can be a big dose for a small pet.
Range 1.4–2.7 mg = 0.75–1.25 tablets of Imodium A-D caplet, 2 mg. For comparison, a typical adult human dose is based on about 70 kg.
Warnings before giving Imodium
- Never give loperamide to MDR1-affected dogs (common in Collies, Aussies, Shelties and herding mixes) unless tested normal.
- Do not use it for bloody diarrhea, suspected poisoning, or in puppies without a vet.
- Constipation, bloating and sleepiness are the common side effects. Stop and call your vet if your dog becomes very drowsy or wobbly.
- If diarrhea lasts more than 24–48 hours, see your vet.
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Questions owners ask
How much Imodium can I give my dog?
The reference range is 0.1–0.2 mg/kg every 8–12 hours. A 44 lb (20 kg) dog comes to 2–4 mg, one or two 2 mg caplets, but only if your dog is not an MDR1-affected breed and your vet agrees.
Which dogs should never take Imodium?
Dogs with the MDR1 (ABCB1) mutation, common in Collies, Australian Shepherds, Shetland Sheepdogs, Old English Sheepdogs, Longhaired Whippets, Silken Windhounds and herding mixes. A cheek-swab test from Washington State University can tell you.