Yesss to probiotics!!!
But I can't give you a brand b/c mine have always been in a combo with a joint supplement, along with the biotin complex and the Omega fatty acids. - either ReitSport by HorseTech (the best all round!!), 4in1 by Med-Vet, or SmartFlex Senior by SmartPak. The ReitSport is pricey at $67 /month, and being a horse addict I won't be able to go back to it until I'm back down to one horse (Soon!! I promise!!), but it takes care of EVERYTHING and my guys never looked or felt so good; it was especially apparent in my aged TB broodmare with arthritis everywhere and difficulty keeping weight on... Wow! New bossmare in the herd!
I'm using the SmartFlex Senior now which lacks the Biotin but is a great deal at $30/mo and it works very well. I like the multis because they're easier and usually much cheaper than buying separately.
I am not one of those who in expressing opinions confines themselves to facts. - Mark Twain
The fact that man knows right from wrong proves his intellectual superiority to other creatures; but the fact that he can do wrong proves his moral inferiority to any creature that cannot. - Mark Twain