You've received some good advice. There are special "senior" feeds available commercially for older horses.
Friends who raise horses had an elderly gelding they kept going quite well. He was well into his mid 30's or older when he finally passed on. Up until the last couple of years of his life, plain alfalfa cubes kept him healthy.
The last couple of years they found if they put his alfalfa cubes into a bucket and added some water, he was able to chew and digest them quite well. Other than good vet care, as recommended here by others, the only other thing they did was provide him with a supplement tub. Their particular supplier was Winn, Inc., a Utah company that makes some good supplements. I'm sure there are other good ones out there. As Barb said, just make sure there is no urea in the supplement if you use a cattle supplement. If you're not sure, just go with a good supplement designed for horses.
<A HREF="http://www.key-lix.com/" TARGET="_blank">http://www.key-lix.com/</A>
Western Horseman magazine featured very elderly horses in a couple of its issues, I think it was last year. I loved reading those issues! The photos and descriptions by the owners were great.
> Thanks everybody for your
> responses. I am gonna have the vet
> check him a little closer this
> time. I am also going to try to
> find the lick Bward was talking
> about.