Illness in horses following spraying with amitraz

Area of Science:

• Veterinary Toxicology
• Equine Health

Background:

• Amitraz is a common acaricide used in veterinary medicine.
• Proper formulation and storage are crucial for pesticide efficacy and safety.

Observation:

• Three out of four horses developed severe clinical signs within 24 hours of application.
• Symptoms included depression, ataxia, muscular incoordination, and impaction colic.

Findings:

• The toxic effects were attributed to the breakdown of amitraz into N-3, 5-dimethylphenyl N-methyl formamidine.
• Degradation products likely caused the observed adverse reactions in horses.

Implications:

• This highlights the importance of using freshly prepared pesticide solutions.
• Proper storage and handling of amitraz are critical to prevent toxicosis in animals.
• Veterinarians should be aware of potential amitraz degradation and its clinical manifestations.