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Loperamide for Dogs & Cats: Diarrhea Treatment & Safety

Published on September 10th, 2024
Updated on November 5th, 2025
Reviewed by Petco's Veterinarian Team

Imodium® is an over the counter antidiarrheal medication formulated for use in humans.

Summary

Used For:

Treatment of diarrhea

Brands:

Imodium®

Species:

Dog, cats (controversial), rabbits, rodents

Other names:

Drug type:

Gastrointestinal

Prescription required:

No

Pregnancy and lactation:

Safety during pregnancy and nursing has not been established.

Side effects:

Constipation, bloat, sedation, ileus (lack of normal intestinal movement), toxic megacolon

General description

Imodium® may be used for the symptomatic treatment of diarrhea in dogs under some circumstances. The use of Imodium® in cats is controversial due to potential side effects. Extra-label use in veterinary species.

Uses

Diarrhea in dogs and reduction of gut motility in rabbits and rodents. Use for the treatment of diarrhea in cats is controversial.

How it works

Loperamide decreases diarrhea by slowing gut motility so that the gastrointestinal contents move through the intestines more slowly.

Dosage

Dogs: 0.08-0.1 milligrams per kilogram of body weight by mouth every 8 hours as needed

Cats: 0.04-0.16 milligrams per kilogram of body weight by mouth every 12 hours (considered controversial, not recommended unless prescribed by veterinarian)

Rabbits and Rodents: 0.1 milligrams per kilogram of body weight mixed in 1 ml of water by mouth every 8 hours for 3 days then once daily for 2 days.

Forms

Imodium® caplets for oral use available in a 2 milligram size. Imodium® liquid suspension for oral use available in 1 milligram per 5 milliliter and 1 milligram per 7.5 milliliter concentrations.

Storage information & handling

Store in a tightly sealed container at room temperature, out of reach of pets and children.

What results can I expect?

Resolution of diarrhea.

Missed Dosage

If a dose is missed, continue with the next dosage at the scheduled time. Do not give two doses at once.

Overdose / acute toxicity

Vomiting, lethargy, weight loss, excess salivation (drooling), and neurologic system depression may occur with an overdose. Herding breeds may be at higher risk for overdose due to a genetic mutation. If an overdose is known or suspected, seek veterinary care immediately.

Side effects

*Constipation

*Bloat

*Sedation

*Toxic megacolon

*Pancreatitis

*Central nervous system changes and/or depression

*Excitatory neurologic effects in cats

Contraindications

*Use with caution and reduce the dose if used in dogs with MDR-1 gene mutations (including many herding breeds)

*Avoid use if diarrhea is caused by bacterial overgrowth or toxin ingestion

*Use with caution in dogs with hypothyroidism, Addison’s disease (hypoadrenocorticism), kidney disease, or a debilitated condition

*Use with extreme caution or avoid use with liver disease, head injuries, or respiratory disease

*Use with caution in dogs under 10 kilograms of body weight due to difficulty in appropriate dosing

Drug interactions

Amiodarone, carvedilol, propofol, progesterone, midazolam, ketamine, imipramine, propranolol, metoprolol, erythromycin, cyclosporine, tacrolimus, medetomidine, ketoconazole, itraconazole, quindine, tamoxifen, and verapamil may all interact with Imodium®.

Precaution

Use with extreme caution in dogs with hypothyroidism, Addison’s disease, kidney disease, debilitated patients, herding breeds or dogs with MDR-1 gene mutations, and dogs under 10 kilograms of body

Sources

Plumb’s Veterinary Drug Handbook

Disclaimer
The information contained on this page is for educational purposes only. This medication should only be given under the advice of a veterinarian who has examined your pet under the laws applicable to your state of residence.

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