Major Uses

Psyllium is a bulk-forming laxative primarily used to treat constipation and profuse watery diarrhea in dogs and cats and sand colic in horses. It may also be used in the management of other gastrointestinal disturbances, such as irritable bowel syndrome.

Psyllium comes from the ripe seeds of the Plantago plant species and works by absorbing water and swelling inside the intestines. This effect slows intestinal transit to ease watery diarrhea, while also triggering bowel movements to ease constipation.

Common Precautions

Psyllium use may cause increased flatulence in some animals. It may take up to 72 hours before psyllium takes effect. Symptoms occurring early in treatment are likely a result of the underlying condition. Overuse of this product may cause constipation.

Psyllium is not for use in rabbits or in animals with existing intestinal obstruction. If vomiting occurs, use must be stopped immediately and a veterinarian should be consulted.

Use of psyllium may cause intestinal and esophageal obstruction in animals that are not given free access to water during treatment. This complication can be life-threatening, but it is easily preventable.

Psyllium is known to interact with various other supplements and drugs, including nitrofurantoin, digoxin, and salicylates. At least 3 hours should elapse between use of any of these drugs and administration of psyllium.

Psyllium should not be used in animals with a known allergy or hypersensitivity to the drug. Any known or suspected overdose should be reported to a veterinarian right away.


Psyllium should be stored at room temperature and protected from moisture. It should be kept in its original packaging and should not be stored in a bathroom or above the kitchen sink.


For small animals, psyllium is available in tablets of 500 mg and 1000 mg. These tablets contain other ingredients, such as barley malt extract. For horses, bulk psyllium is available in pails containing 28 oz, 56 oz, 1 lb, 10 lb, and 30 lb.

Dogs undergoing treatment with psyllium should be dose at 1 to 5 g/lb (2 to 10 g/kg) every 12 to 24 hours. For cats, the typical dose is 0.5 to 2 g/lb (1 to 4 g/kg) every 12 to 24 hours.

Doses may vary in different species, when the drug is given by a different route or concurrently with other medications, and with regards to a patient's age, breed, and health status. A veterinarian's dosing instructions and/or those printed on the medication label should be followed closely.

If a dose of psyllium is missed, it should be given right away. If it is almost time for the next dose, the missed dose should be skipped and the normal schedule resumed. Two doses of this medication should not be given at once.

This information is for general reference only and should not be used for the diagnosis or treatment of any condition of your pet. It's intended as a general reference, this information may not include all possible uses, precautions, directions, reactions (including allergic), drug interactions, or withdrawal times. Always consult your local veterinarian and have your pet examined for any advice concerning the diagnosis and treatment of your pet, including which products and doses are most appropriate. Any trademarks are the property of their respective owners. VetDepot is not a pharmacy. All prescription products are dispensed by our Pharmacy Partner. Article last updated 2/2014.