What Makes Your Horse Feel Stressed?

Horses notice everything! Anyone who works with horses soon realizes that they keep an eye on their surroundings, paying particular attention to any sound, sight, person, or situation that is the least bit out of the ordinary.

Remembering that horses are prey animals helps to explain this hyperalert trait: instinct tells a horse that its safety depends on noticing changes (potential threats) in its environment and being ready to run away from perceived dangers.

Increases in heart rate and cortisol production are two markers that can indicate elevated stress levels in horses. Even if your horse doesn’t outwardly show excitement in certain situations, these signs of stress may be present and can be monitored to determine the level of excitement.

A study of 25 young Warmblood geldings was conducted in Denmark. First, the researchers observed the horses interacting in a pastured group to find the social ranking of each horse. They checked the cortisol level in droppings from the horses to establish a base level of this hormone, which is commonly accepted as an indicator of stress. Each horse was then tested for fearfulness, a trial in which the horse’s behavioral reaction to a surprising object was noted.

The researchers compared heart rates when a horse was being taught something new, both in familiar surroundings and at a new location in a competition setting a month later. The task was to learn to sidepass when the handler cued the horse with a whip. Higher heart rates (average increase of 12 beats per minute) were noted when the horses were trained in the unfamiliar location compared to training at home. The horses did not learn as quickly in the new environment, with performance decreasing as heart rate increased. This was seen as an indication of how these young horses might perform in the unfamiliar environment of a show ring.

Other findings showed that individual heart rate and fearfulness level did not relate to how horses performed at home. However, there was a correlation in the strange environment, with the most fearful horses showing the lowest performance level. Finally, there was no correlation between good home performance and good performance in a new environment. Therefore, it would be difficult to predict performance away from home for these horses based on their performance in familiar surroundings.

Basic stress level was related to social ranking, with higher social rank associated with lower levels of stress. The basic stress level and social rank could not be correlated with performance, either at home or in a competition setting.

So, what makes your horse feel stressed? Low social status, being confronted with strange or surprising objects, and being away from home are all situations that may be associated with high stress levels. Other studies have shown that a horse’s heart rate goes up when a human, even a familiar one, simply enters the horse’s stall, and tacking a horse up is another pulse-booster. Anyone working with horses, especially young ones, should keep these facts in mind during training. Following a quiet routine while gradually introducing new experiences will help to establish a secure, trusting relationship with a young horse.