Diethyltoluamide is a fly repellent used on horses and ponies. Active ingredient DEET is safe on all natural surfaces, including skin and hair. An effective insect repellent in specialized equine fly sprays formulated with safe, capped concentrations for horses.

• Patch test:

  If your horse has sensitive skin or you are using a DEET-based product for the first time, perform a patch test 48 hours before full application. 

• Avoid sensitive areas:

  Do not spray DEET directly on mucous membranes or on broken or irritated skin.