I apply a small amount of Derfen Original to the skin between the hairs at one itchy spot on the mane. I massage it in very gently. Then I apply a small amount of Derfen Clear to an itchy spot at the top of the tail, on the skin between the hairs (like a dye). I massage gently. If only the tail or mane needs testing, test Derfen Original on the affected area first.

I check the areas and look for signs of scratching, ensuring the skin is healthy and free of flaking. The Derfen product suitable for your horse's skin is the one that shows a moisturized area, with little or no flaking and no signs of scratching or broken hair since the previous day.

If only the tail or mane needs to be tested, first test the Derfen original on the affected area.

If only one Derfen product was tested the day before on a specific area, check the areas and see if there are any signs of scratching, if the skin is healthy and has little or no dandruff. If this is the case, the original Derfen is suitable for your horse's skin. If there is a lot of dandruff and signs of scratching, Derfen Clear will be more suitable. Wait until the next day to apply it.