Now you may be thinking, "All my horses do is stand around and eat all day. How could they be stressed?" Well, historically horses were prey animals that lived in herds grazing for the majority of the day, so it is not surprising domesticated horses experience some degree of stress from modern day practices such as stall confinement. Dr. Camie Heleski from the University of Kentucky indicates at the Horse.com that as horse owners, we need to try to decrease this stress as much as possible. One method to determine the level of stress in horses is to measure stress hormones, one of which is cortisol and can be measured in blood, saliva or feces. Another method to examine stress is by monitoring body actions including rolling, standing, rearing, weaving and kicking as well as positioning of the tail, neck, ears, mouth and head. And just like people, horses are individuals because some situations might stress some horses but not others.
One type of stress is feed related from restricting grazing and preventing access to hay throughout the day. Horses can experience gastrointestinal discomfort if deprived of food for more than two hours. Also, mares not allowed continuous access to feed or grazing are less fertile due to stress. Fecal cortisol levels also increase when horses are transported and increased cortisol levels can increase chances of respiratory infections occurring. Housing-related stress also occurs; when horses are housed individually with no contact with other horses, fecal cortisol levels increase. So it is important to realize that decreased feeding, isolation from other horses and transportation are all stresses that affect our horses, and knowing the cause of stress can help us to decrease it.