I've never heard of it but personally if your dog is older and having some issues or for any dog really I would look into NuVet Plus by NuVet Labs. Its some really good stuff and I have seen a HUGE difference in giving it to my Pit who has bad allergies. I hope to get Tuesday on it before we start showing.
To clarify and expand upon the previous Cholodin post:
Dogs get some of the same symptoms in their old age that humans do, for many of the same reasons. Plaque builds up in vascular systems, and they get vague. Canine Cognitive Dysfunction, or Cognitive Dysfunction Syndrome is what it's called. Google that, for more information. I didn't realize it until I did my research. I also didn't realize it could be reversible!
Confusion, staring off into space, or at a wall, bookcase etc. Lack of coordination, not responding to commands, hearing loss. Change of sleep patterns (sleeping all day and wandering around at night). They forget where to pee (!!), they forget who people are, name and command recognition, etc. A lot like Alzheimer's in humans.
My vet did a little research on Cholodin, and was very impressed with the results. She also said that it shouldn't have any effect on Alex's thyroid supplements, or really, any other pharmaceutical. A trainer we've used has also seen great results with Cholodin. I've got some coming in the mail, as I couldn't find it at all locally.
Other strategies include giving more commands, working with old obedience routines, sort of a "use it or lose it". Exercise helps too. Antioxidants were also recommended.
I'll post here about any results I get, as you'll all have Senior dogs eventually... God Willing...