I used to give corta-flex to my guy - and would definitely use it again, except my barn lady just charges me ten bucks a month to keep him on what she uses for her horses (Vita Flex MSM). I couldn't pass up a good deal and it seems to work for him. He only needs the chiropractor every 3 months or so? And he's strong and sound.
Early summer I had a freak out when I saw how thin he looked again and we had a vet come out and do a full blood check. My barn lady and I were literally crying over the phone while we discussed end of life decisions that I might need to make. I broached the subject because I felt he was not thriving. I saw his dad and grandmother go through the same thing before their health started failing. His grandmother was in her 40's and darn it but I'm hoping he lives that long as well.
Blood test showed he was anemic. So my barn lady got him on Red Cell and that made a huge difference. He started eating better and had more energy out in the field. He still is too thin, but he's sound as an ox for once.
Those are two two main supplements. There are a couple other things... like the vet thinks he had the beginning stages of cushings. My barn lady and I don't believe it, but he's getting that supplement in his food.
The senior feed is supposed to boost things for him and help him keep weight on. I've given Source and a couple other supplements some thought, but we will see how he does this winter. I've definitely given my barn lady full permission to keep the vet on speed dial and I want him to get extra food and extra hay in his stall to keep him healthy. Last winter he lost weight and I don't want that to happen again. Normally by this time of the year he should be getting a nice layer of fat. >- And I know that my barn lady is skimping on hay too (not with him) because of the shortage. >.<
The great thing though is he's still a sweetheart. He's MEAN to the other horses (stud brain), but like when I go there with Jacks I never worry about Zorro stepping on him or biting him. Jacks will lay down and just hang out in the stall with us while I groom, and Zorro only will do the nose snuffle at Jacks' head or back.
ETA - Oh, the blanket has "Zorro" sharpied a few times on it. So I should find it easily. It depends on what the spare looks like. The one I got last year was longer to provide more warmth and coverage for him. Even if he looked like he was wearing a dress.