I've been using the Absorbine Ultrashield. Be warned, though, they have changed the formulation and the product is now called Ultrashield EQ (I think it's EQ--there's some letters after the name). It is not the same as last year's version--I've had several people tell me that they used the new version & their horses had serious reactions to it--major hair loss & irritated skin, seems to me some blistering on some of the horses.
No, they didn't apply it too strong or too often, it's just something in the new formula that is very harsh on skin. I don't know as it affects all horses badly, but definitely some react to it even though they had no trouble with the original version. I haven't bought any yet this spring--now I'm not sure I want to risk trying it to see of my horses are okay with it. So, I'm not sure what I'll be using this year.
Just something for Ultrashield users to be aware of!