How to Order Prescriptions Description When administered under labeled conditions, ReBalance is an FDA-approved, safe and effective treatment for horses with equine protozoal myeloencephalitis (EPM) caused by Sarcocystis neurona. Proven safe and effective Cost-efficient Easy administration Oral suspension FDA-Approved From A Name You Can Trust The active ingredients (sulfadiazine 250 mg/mL and pyrimethamine 12.5 mg/mL) inhibit folic acid synthesis at two different sites, in the same synthetic pathway. The combination is synergistic, with the drug combination having an anti-protozoal effect. Equine protozoal myeloencephalitis (EPM) is a nervous system disease caused by the protozoa Sarcocystis neurona. Horses develop the disease by ingesting contaminated feedstuffs. The definitive host is the opossum, but intermediate hosts have been identified as the nine-banded armadillo, the striped skunk and the raccoon. EPM is an elusive disease as it 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. It has been estimated that up to 55% to 65% of horses respond favorably to treatment. However, it is further estimated that a small percentage (no more than 10%) of treated horses do recover completely. Dosing 4 mL per 110 lb (50 kg) of body weight once per day. The duration of treatment is dependent upon clinical response, but the usual treatment regimen ranges from 90 to 270 days. by PRN