Imodium(®) (loperamide) is a medicine which can be used to treat dogs with diarrhea. It acts directly on the intestinal wall to keep the absorption of water and electrolytes under control and to prevent waste from being pushed through the digestive tract too quickly. When waste is pushed through the digestive tract too quickly the intestines don’t have enough time to properly absorb fluids leading to a watery stool. For treating diarrhea you can use either the plain formula (Imodium A-D or EZ Chews) or Imodium Multi-Symptom Relief.

Safer cure for doggy diarrhea:

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Recommended Dosage

Note: Even though the medicine can be purchased over-the-counter it may not be suitable for all dogs. You should always talk to your vet before giving your dog any product containing loperamide.

The medicine can be given in two ways, either by pouring the liquid onto your dog’s food or by having them swallow the caplets or EZ Chews. The meals you feed when treating diarrhea should be bland, consisting of three cups of plain rice and boiled chicken or boiled beefburgers. It’s best to not continue treatment beyond 5 consecutive days and to contact a vet if symptoms haven’t improved after 48 hours.


Imodium A-D contains 1 mg of loperamide for every 7.5 mL of liquid and can be given to dogs at a dosage of 0.3 – 0.6 mL/lb twice to three times daily. If you’re using a generic medicine the amount of liquid you need to give per dose could be different, be sure to check the concentration and ask a vet for assistance. When it comes to treating larger dogs we advise using tablets (if possible) to avoid having to give them large amounts of liquid which they tend to hate the taste of.

A chart of the Imodium A-D liquid dosage for treating a dog
Dog’s Weight In Pounds: Dosage In mL:

A-D Caplets and EZ Chews

If you decide to use the EZ Chews or A-D caplets you should give your dog one 2 mg caplet or chew for every 25 – 50 lbs they weigh two to three times per day.

Multi-Symptom Relief

Imodium Multi-Symptom Relief tablets each contain 2 mg of loperamide and 125 mg of simethicone. Simethicone is safe for dogs and has been given at up to 8 grams without causing any serious side effects (just loose stools). This medicine is safe to use and should be dosed at one pill per 25 to 50 pounds of body weight.

Example: A 40 lb dog would usually need one 2 mg A-D caplet or EZ Chew, or around 20 mL of the liquid per dose.

Can I Give My Dog Imodium?

Yes, but those with the MDR1 gene mutation are more likely to experience sedation. This mutation is common in these breeds:

  • Collies
  • German/Australian Shepherds
  • English/Old English/McNab/Shetland Sheepdogs
  • Longhaired Whippets
  • Silken Windhounds
  • Skye terriers

If your pet is a mixed breed or if you think they may have the MDR1 mutation you can get them tested by asking the vet.

What is the MDR1 gene?

The MDR1 gene is responsible for producing a protein known as “P-glycoprotein” which removes toxins from the brain. When the gene is mutated the body may not be able to properly remove harmful substances from the brain. Learn more here.

Other contraindications…

This medicine should not be given to pregnant or nursing dogs or to puppies under 6 weeks of age. If the diarrhea has been caused by eating a toxic substance, using loperamide could prevent its removal from the body leading to a number of problems.

Guidelines For Use

For safe treatment with this medicine we recommend following these guidelines:

  • Talk to a vet before using this medicine
  • Tell a vet if your dog has ever reacted badly to ivermectin
  • Tell the vet about any medical conditions your pet suffers from
  • Tell the vet about any other medicines or supplements you are giving to your pet
  • Provide plenty of water to replace the fluid they are losing
  • Feed bland food such as plain rice and boiled beefburgers
  • Contact the vet if symptoms don’t improve after 2 days
  • Do not continue treatment for longer than 5 days

Diarrhea causes water and electrolytes to be lost from the body which can lead to dehydration. This is why it’s especially important to provide plenty of water and essential minerals until the symptoms of diarrhea have gone away.

What Is It Used For

The medicine is used to slow the passage of waste through their intestines and to allow electrolytes and water to be properly absorbed back into the system. It can also be used to:

  • Reduce the amount of stool produced
  • Treat diarrhea caused by irritable bowel syndrome (IBS)

Loperamide can effectively treat diarrhea caused by fluid build up or intestinal muscles contracting too quickly.

Side Effects

A dog treated with loperamide could experience any of the following side effects:

Most Common

  • Sedation
  • Flatulence
  • Constipation


  • Intestinal paralysis
  • Toxic megacolon
  • Pancreatitis

Sedation is more common when the MDR1 gene mutation is present. Always call the vet in the event that your pet suffers any serious reactions to the medicine.


An overdose could cause strong sedation as well as anorexia, salivation, hypothermia and a slow heart rate. 2.25 mg/lb of loperamide could be life threatening, but a 50 lb dog would need to have swallowed 57 or more tablets to reach this amount. If you suspect an overdose you should call your vet for professional advice immediately or ring the ASPCA Animal Poison Control hotline on (888) 426-4435.