My horse used to be an itch monster, too. However, I had a clue as to what was wrong because one (and only one) of her eyes seemed to water quite a bit. I asked my vet if she had allergies – and he said possibly so. He recommended I try (sorry smartpak!) the skin/allergy supplement made by Platinum Performance. It’s a little expensive (around $96/jar), but it lasts a couple of months.
That stuff has made such a difference! I’ve discovered that, here in Texas I only have to give it to her from April-October. But, it has markedly reduced her itching (and no eye/nose runny-ness).
It may not be the solution for you – but, it made a huge difference for her. I also use one of the smarpack coat supplements and did reduce the baths… but the biggest difference was the allergy formula.
It can’t hurt.