What horses find stressful

We all have our individual triggers, and it’s just the same with horses — what one horse might perceive as stressful may not necessarily appear anxiety-inducing to another. For example, if two horses go hacking together, only one might spook at a bird flying up from the hedgerow. Likewise, some horses hate hacking alone, while others are fine. However, there are a number of commonly accepted equine stressors, including the following:

■ Feeding-related stress

It’s well known that horses are trickle feeders who would naturally eat forage almost continuously for between 40 and 70% of each 24-hour period. They can experience both physical and psychological distress if deprived of food for even just an hour. Researchers have linked dietary restrictions (ie, not permitting free-choice forage consumption) to the emergence of oral stereotypies such as windsucking and other behaviours, together with gastric ulceration. Numerous studies confirm that semicontinuous feeding of roughage might be a way to fulfil the basic needs of the horse’s digestive system, reduce stress, and promote overall wellbeing.

■ Pain and physical discomfort

Physiological stressors, such as pain or disease, extremes of temperature, and a repetitive or demanding workload, are all known to cause anxiety.

■ Emotional discomfort

Such as weaning, changes in herd structure, separation anxiety and particularly transport — this is known to cause extreme stress and even, in some cases, leads to an increased risk of colic.

■ Pregnancy and reproductive stress

Having a baby is hard work. Even a common procedure such as an ultrasound probe in pregnancy can cause significant stress. Research suggests that an internal ultrasound may even contribute to pregnancy loss.

■ Housing or environmentrelated stress

Horses who are stabled individually and have no contact with other horses suffer higher levels of stress. Problems also occur if their stable is too small, the yard is too noisy, or they have insufficient turnout.