Equine piroplasmosis treatment protocols: specific effect on orocaecal transit time as measured by the lactose 13C-ureide breath test.

This study investigates the side-effects of a commonly used drug for horse parasites, imidocarb dipropionate, specifically how it affects the digestive system of horses, and explores whether any adverse impacts can be mitigated by using certain pre-treatments.

Overview of the research

• The researchers conducting this study were aiming to address the issue of negative side effects – namely colic and diarrhoea – experienced by horses when treated with the drug imidocarb dipropionate for a parasitic infection known as equine piroplasmosis.
• The researchers used a specific diagnostic tool, the lactose 13C-ureide breath test, to measure changes in the transit time of ingested material through the horse’s large intestine, or ‘orocaecal transit time’ (OCTT), in response to the medication.
• The main hypothesis was that treatment with imidocarb dipropionate would both cause colic and reduce OCTT, but these effects might be lessened if the horse was first given a pre-treatment of either atropine or glycopyrrolate.

Details of the experimental design

• The experiment was conducted on six healthy horses and employed a double-blind randomised control design (neither the horses nor the researchers knew which treatments the horses were receiving).
• Three treatments were compared. In one, horses were injected with imidocarb and given a saline solution as a placebo; in the second, horses were premedicated with atropine before being treated with imidocarb; and in the third, they were premedicated with glycopyrrolate before the imidocarb treatment.
• The impact of the different treatments on OCTT was measured using the lactose breath test, and statistical analysis was conducted to determine the significance of any observed changes.

Findings of the study

• It was found that pre-treatment with atropine resulted in a significant increase in OCTT compared to treatment with imidocarb alone.
• Four of the six horses treated with imidocarb alone developed colic and diarrhoea, whereas these symptoms were not observed in the horses premedicated with atropine or glycopyrrolate.
• Based on these findings, the study concludes that premedication with glycopyrrolate is recommended prior to treatment with imidocarb for equine piroplasmosis to prevent the onset of gastrointestinal distress, as this drug did not result in the same inhibition of gastric and small intestinal motility observed with atropine.