Major Uses

Nitazoxanide is an antiparasitic agent that is used to treat a variety of protozoa, bacteria, nematodes, and trematodes. It is useful against sarcocystis neurona, giardia, cryptosporidia, and helicobacter pylori. The oral form of nitazoxanide is effective in treating horses with equine protozoal myeloencephalitis caused by sarcocystis neurona.

Common Precautions

Nitazoxanide should not be used in horses that are less than one year old, sick or debilitated. It should be used cautiously in patients predisposed to laminitis, and in patients with compromised renal or hepatic function.

Some negative side effects associated with nitazoxanide include fever, lethargy, depression, reduced appetite, and anorexia. Patients may also experience decreased gut sounds, loose or discolored feces, diarrhea, scant feces, laminitis, increased water consumption, discolored urine, head and/or limb edema, and weight loss. Stallions in particular are prone to laminitis. Enterocolitis is also a possible side effect of nitazoxanide.

Nitazoxanide should not be used in animals with a known allergy or hypersensitivity to the drug. A veterinarian should be contacted immediately if an overdose is suspected, the symptoms of which can be intense salivation, increased liver and spleen weights, anorexia, diarrhea, and lethargy.


Nitazoxanide should be kept at a temperature of 77 degrees Fahrenheit and stored in a tight, childproof container that is resistant to light. It can stand instances of temperatures between 59-86 degrees Fahrenheit, but should otherwise stay at the normal holding temperature. When mixed with liquids, the drug should be kept at room temperature and held no more than a week before discarding.


When treating equine protozoal myeloencephalitis in horses, doses normally start at 25 mg/kg once daily for the first 5 days of treatment. For days 6-28 of treatment, 50 mg/kg once daily is a typical. This should be extended from a 28 day treatment to a 56 day treatment when treating relapsing EPM. Nitazoxanide has been used to treat cats for cryptosporidia-associated diarrhea. Cats typically receive a dose of 25 mg/kg every 12-24 hours until the condition resolves. Should a scheduled dose be missed, it should be administered as soon as possible. If it is almost time for the next scheduled dose, the missed dose should be skipped and the regular medication schedule should be continued. Two doses of nitazoxanide should not be administered at the same time.

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.

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.