After being treated with a spray solution containing amitraz, three of four horses exhibited signs of illness, such as tranquilization, depression, ataxia, muscular incoordination, and impaction colic. Treatment and recovery were achieved through strenuous symptomatic measures, which included the use of intravenous fluids, analgesics, and other medications.

Background

• The research revolves around the circumstance where horses fell ill after being sprayed with an aqueous suspension of amitraz, a chemical often used in pesticides and ectoparasiticides.
• Amid the four horses, three got sick within 24 hours of the spraying, likely due to the highly toxic N-3, 5- dimethylphenyl N-methyl formamadine derivative that the amitraz in the older solution had decomposed into after about three weeks.

Clinical Signs and Symptoms

• The affected horses exhibited various clinical signs of illness: tranquillisation, depression, ataxia (lack of voluntary control of muscle movements), muscular incoordination and impaction colic (severe constipation) that lasted up to six days.
• One horse also developed subcutaneous edema (swelling caused by fluid accumulation) in the face.
• These adverse effects were accompanied by mild dehydration and acidosis (excess acidity in body parts).

Treatment and Recovery

• All the horses survived this ordeal. Their recovery was achieved by persistent symptomatic treatment that comprised the administration of intravenous fluids to counter dehydration, enemas and analgesics every three hours to relieve pain and discomfort from impaction colic, multiple doses of paraffin oil orally for constipation, and dexamethasone intravenously to reduce inflammation.
• After the resolution of their constipation, the horses had diarrhea for about 24 hours until their condition finally returned to normalcy.

Implication

• This research study illustrates the potential toxic effects of amitraz, especially when it is part of an older solution. It is a significant reminder for those in equine care regarding the usage of such chemical substances and the need to ensure their freshness to prevent hazardous breakdown products from forming.