Daily feeding of diclazuril top dress pellets in foals reduces seroconversion to Sarcocystis neurona.

This research studied the effects of daily feeding of diclazuril pellets on foals and found that it helps reduce the likelihood of the foals seroconverting – developing antibodies – to Sarcocystis neurona, a protozoan parasite.

Study Design and Participants

• The study involved 33 foals from a farm notorious for high rates of exposure to Sarcocystis neurona. Sarcocystis neurona is a parasite that affects the nervous system and can cause equine protozoal myeloencephalitis, a dangerous neurological disease in horses.
• These foals were split into two groups – one was untreated while the other was treated with diclazuril, a common antiprotozoal medication.

Methods

• From the age of 1 to 12 months, the treated foals were given daily doses of 0.5 mg/kg of diclazuril pellets.
• Monthly blood tests were conducted on the foals to identify the presence of IgG antibodies against S. neurona using the indirect fluorescent antibody test.

Results

• The researchers observed a continuous drop in seroprevalence or the proportion of foals showing positive results for S. neurona antibodies after ingesting colostral antibodies. This was the case for both groups of foals until they reached weaning age.
• However, there was a notable increase in the seroprevalence among the untreated foal group post-weaning, compared to those that received daily diclazuril.
• The distinct difference in seroprevalence over time indicates that the daily low-dose of diclazuril effectively reduced the potential of infection from S. neurona in foals.