•High Pulse and Respiration
When a horse becomes stressed, their pulse and respiration rates can increase, sometimes drastically. Know your horse’s basic TPRs.
•Sweating
As a horse's pulse and respiration may increase when stressed, it may start to sweat (and tremble). Work stress tends to show up between the horse's legs, and under the saddle area and can eventually cover the horse's whole body. It depends on how hard and long the horse works. A stressed horse may sweat in patches however. Patches of sweat can also show the location of old injuries.
•Bolting Food
A worried horse often bolts it's food. Bolting can lead to choke. Learn more about choke. This can happen in a stall or trailer.
•Chewing or Biting
Some horses express stress by biting things, people or other horses.
•How to Alleviate Stress
Much stress can be relieved by providing consistent schedules in as natural environment as possible. This means frequent turn out, with ample access to food, water and companionship. Show stress is more difficult to remedy, but turn out and exercise between shows can be helpful. Give horses time to acclimatize to new situations, such as new herd mates or stall locations. Do your best to give horses in trailers a smooth ride. It's almost impossible to prevent all stress, but good basic care should take care of most.