You have to start applying Spot On well before midges etc become a nuisance - the product needs to be able be absorbed into the horse's skin in advance for optimum benefit.
My son's pony had chronic sweet itch - to the point she would rub herself raw, even with tea bags rugs on (as in the mesh sort!). Started applying Spot On ten years ago and she now has a full mane and tail and, as long as the product starts to go on early spring, she doesn't have a reaction any more. But you do have to apply it regualrly and be very methodical, which is why people believe it doesn't work on their ponies.
My son's pony had chronic sweet itch - to the point she would rub herself raw, even with tea bags rugs on (as in the mesh sort!). Started applying Spot On ten years ago and she now has a full mane and tail and, as long as the product starts to go on early spring, she doesn't have a reaction any more. But you do have to apply it regualrly and be very methodical, which is why people believe it doesn't work on their ponies.