Shampoos are commonly used topical treatments. Before applying a medicated shampoo, wash the horse with a cleansing shampoo and rinse well. Medicated shampoos often are not good cleansing agents, do not lather well, or do not work except on a clean hair coat.
The medicated shampoo should be applied evenly to the hair coat after being diluted in water. (The shampoo should never be applied directly to the skin.) Diluting the shampoo will help rinse it from the coat and minimize the potential for irritating the skin. Depending on the shampoo, dilute 1 part shampoo to 3 or 4 parts water. The water used should be lukewarm, never hot.
If possible, keep the medicated shampoo on the skin for 10 minutes (or as directed) then rinse thoroughly. Shampoo residue is a common cause of skin irritation or allergic reactions in horses, so it is very important to rinse your horse carefully and fully follow all instructions.
Medicated shampoos usually need to be used frequently for the most successful results. Ask for and follow your veterinarian’s instructions on shampoo frequency.