Corticosteroids are a group of natural and synthetic analogues of the hormones secreted by the pituitary gland. These include glucocorticoids, such as dexamethasone, flumethasone and ?-methasone. Synthetic glucocorticoids are commonly used in veterinary medicine as anti-inflammatory agents, and illicit use as growth-promoters is suspected. Dexamethasone is rapidly absorbed and excreted in urine and faeces, primarily as the parent molecule, tracer and inactive 6-hydroxy metabolites. (3)