Vitamin B1 is natural help for horses under stress.

Studies show that many performance horses can be helped by the addition of thiamin (vitamin B1) to their diets. If a performance horse on good nutrition shows a loss of weight or appetite, a dull coat, muscle tremors, cramps, diarrhea or nervousness, there is a good chance that Thiamax can help. Thiamax is pure thiamine mononitrate in a stable, palatable wheat germ base that your horse will eat right out of your hand.

Thiamine (min) ... 16,000 mgs./lb..