(sulfadiazine/pyrimethamine Oral Suspension)
  • Category
    Equine Health
  • Species
  • Supplied

    946.4 mL (one quart)

FDA Approved, Safe And Effective Treatment For Horses With Equine Protozoal Myeloencephalitis (EPM).


For use in horses only. Do not use in horses intended for human consumption. Not for human use. Keep out of the reach of children.
Prior to treatment with ReBalance® Antiprotozoal Oral Suspension, EPM should be distinguished from other diseases that may cause ataxia in horses. Injuries or lameness may also complicate the evaluation of an animal with EPM. In most instances, ataxia due to EPM is asymmetrical and affects the front and/or the hind limbs.

Treatment may cause generalized bone marrow suppression, anemia, leukopenia, neutropenia and thrombocytopenia. A complete blood count (CBC) should be performed monthly to monitor horses for development of these conditions. The administration of the drug may need to be discontinued and/or treatments for bone marrow suppression initiated.

Other, less frequent side effects included decreased appetite, loose stools, and mild colic. In most cases, the gastrointestinal signs were self-limiting and did not require discontinuation of treatment.

Worsened neurologic deficits (treatment crisis) may be observed during a period beginning with the first few days of treatment with ReBalance and ranging out to 5 weeks. This neurologic deficit exacerbation may be the result of an inflammatory reaction to the dying parasites in the CNS tissue.

The safe use of ReBalance® Antiprotozoal Oral Suspension in horses used for breeding purposes, during pregnancy, or in lactating mares has not been evaluated. The safety of ReBalance with concomitant therapies in horses has not been evaluated.

ReBalance is not for use in horses with known hypersensitivity to sulfonamide drugs or pyrimethamine. Refer to the prescribing information for complete details.

(sulfadiazine/pyrimethamine Oral Suspension)

An oral suspension for horses with equine protozoal myeloencephalitis (EPM) caused by Sarcocystis neurona.

NADA# 141-240

EPM is a nervous system disease that horses develop by ingesting contaminated feedstuffs with the protozoa Sarcocystis neurona.

EPM presents highly variable clinical signs that may range from head tilt, ear droop, blindness, seizures, inability to chew or swallow, gait abnormalities, stumbling, muscle atrophy, weakness, incoordination, ataxia, or depression. Testing and development of an early, effective treatment plan should be considered.

ReBalance, when administered under labeled conditions, is an FDA-approved, safe and effective treatment for horses with EPM caused by Sarcocystis neurona.

ReBalance® Benefits:

  • FDA-Approved, From A Name You Can Trust
  • Patented Combination: 5,747,476; 6,255,308; 6,448,252
  • Economical

CAUTION: Federal law restricts this drug to be used by or on the order of a licensed veterinarian.
  • Detailed Overview
  • Resources
  • FIOS

Detailed Overview


For the treatment of horses with equine protozoal myeloencephalitis (EPM) caused by Sarcocystis neurona.

Dosage and Administration

Dosing directions provided are for guidance only. Federal law restricts this drug to be used by or on the order of a licensed veterinarian.

Active Ingredients

Sulfadiazine and Pyrimethamine. The active ingredients in ReBalance®, Sulfadiazine and Pyrimethamine, are a well-known therapy for treatment of this disease. The combination of Sulfadiazine and Pyrimethamine is synergistic, with the drug combination having an antiprotozoal effect.¹

1Granstrom DE. Understanding Equine Protozoal Myeloencephalitis: Your Guide to Horse Health Care and Management. The Blood-Horse Inc., 1997;10.