Weaving is a locomotor stereotypy in horses characterized by rhythmic side-to-side swaying, caused by management factors that can be prevented or mitigated through environmental modification.
Weaving represents a management-induced welfare problem that serves as a clear signal that an individual horse's behavioral needs are not being met. The swaying movement patterns characteristic of weaving begin as attempts to seek social contact or respond to anticipatory feeding excitement, and become neurologically entrenched through repetition into stereotypic behavior. The welfare-appropriate response to a weaving horse is to address the management causes rather than physically preventing expression through grilles - which causes frustration and additional welfare harm without resolving the motivation. Prevention is straightforward: maximize turnout, provide forage ad-lib, ensure visual contact with other horses.