Weaving in Horses

What is weaving?

Weaving is a stereotypy exhibited by some horses in which they move their head and neck from side to side while shifting their weight from one foreleg to the other in a rhythmic movement. Stereotypies are repetitive behaviors that lack an apparent goal or function. They are often induced by stress, frustration, and/or dysfunction of the central nervous system. 

Affected horses may weave for hours each day, leading to weight loss, decreased body condition score, dehydration, muscle fatigue, and tying up (rhabdomyolysis). Weaving can also lead to excessive and uneven wearing of the hooves or shoes.

Horses from certain breeds may have a genetic predisposition to exhibit weaving behavior. Some researchers have suggested that this may be due to the more reactive temperaments of particular breeds, but other studies did not find associations between reactive temperaments and the prevalence of stereotypies. Similarly, proposed associations between a horse’s sex and the tendency to develop stereotypies are confounded by notably different management techniques between stallions, who often spend more time away from other horses, and mares and geldings, who generally spend more time in close proximity to other horses.

What causes weaving?

As with other equine stereotypies, weaving is a response to chronic stress brought on by environmental conditions such as social isolation, restricted movement, inability to see other horses, and food-related anticipation or frustration. Environmental factors early in life, such as stressful weaning, may increase the risk that a horse will develop a stereotypy such as weaving.

How is weaving treated?

Treatment for weaving involves providing the horse with a larger stall, or ideally, regular access to pasture. Affected horses may also benefit from increased exercise and having a visual line to other horses. Studies have reported a reduction in weaving behavior after the addition of a window or a mirror to the stall environment. Stall toys may be beneficial, particularly for young horses. Weaving bars are sometimes added to stalls to prevent the behavior, but often just shift the horse’s movement to the back of the stall.

It can be especially challenging to treat stereotypical behaviors in adult horses. However, for adult horses that weave, all efforts should be made to reduce the amount of time that they perform the behavior by incorporating the above methods.

How can weaving be prevented?

As with other equine stereotypies, weaving is a complex behavior that is likely influenced by a combination of genetics and environmental factors. This often makes them difficult to prevent. Considerations related to an open stable design and the implementation of low stress weaning practices may reduce stressors that lead to weaving. Ensuring that horses have appropriate access to pasture, forage, as well as regular exercise, may also help prevent the behavior, especially in young horses.