New Study Confirms Rapid Action of PROTAZIL® (1.56% diclazuril) Antiprotozoal Pellets for the Treatment of EPM
A recent study has examined PROTAZIL®, a pelleted antiprotozoal treatment for equine protozoal myeloencephalitis (EPM), a neurological disease in horses caused primarily by Sarcocystis neurona. The research shows that diclazuril, the active ingredient in PROTAZIL, reaches therapeutic levels in the cerebrospinal fluid (CSF) within 12 hours of a single oral dose.
EPM can result in symptoms such as incoordination, muscle weakness, and gait abnormalities. While a significant portion of U.S. horses has been exposed to S. neurona, only some develop clinical disease. Early treatment is associated with improved outcomes.
Study Highlights
Conducted at North Carolina State University, the study involved six healthy adult horses.
Horses received a single oral dose of diclazuril (1 mg/kg top-dressed on sweet feed).
Therapeutic levels in CSF surpassed the minimum inhibitory concentration (MIC) for S. neurona within 12 hours.
CSF levels peaked at 24 hours and remained above the MIC for eight days, indicating sustained activity.
Plasma levels peaked later at 48 hours, highlighting the importance of measuring drug concentrations in the CSF.
Lead researcher Kate Hepworth-Warren, DVM, DACVIM-LAIM, emphasized that rapid achievement of therapeutic levels is particularly important in acute EPM cases, as early intervention can improve clinical outcomes.
Implications for Veterinarians and Horse Owners
The study provides additional data on the speed and duration of diclazuril activity, supporting its use in EPM treatment protocols. Horse owners are encouraged to consult with their veterinarians to determine whether PROTAZIL is appropriate for their horse.
For complete prescribing and safety information, refer to the PROTAZIL label.
Safety Notes:
Not for use in horses with hypersensitivity to diclazuril.
Safety in breeding, pregnant, or lactating horses has not been evaluated.
Not for horses intended for human consumption.
