Detomidine

[3] α2-adrenergic agonists produce dose-dependent sedative and analgesic effects, mediated by activation of α2 catecholamine receptors, thus inducing a negative feedback response, reducing production of excitatory neurotransmitters.

Due to inhibition of the sympathetic nervous system, detomidine also has cardiac and respiratory effects and an antidiuretic action.

[4] A profound lethargy and characteristic lowering of the head with reduced sensitivity to environmental stimuli (sound, pain, etc.)

A short period of reduced coordination is characteristically followed by immobility and a firm stance with front legs spread.

Following administration there is an initial increase in blood pressure, followed by bradycardia and second degree atrioventricular block (this is not pathologic in horses).