Isoxsuprine (used as isoxsuprine hydrochloride) is a drug used as a vasodilator in humans (under the trade name Vasodilan) and equines. Isoxsuprine is a beta-adrenergic agonist that causes direct relaxation of uterine and vascular smooth muscle via beta-2 receptors.

Isoxsuprine is most commonly used to treat hoof-related problems in the horse, most commonly for laminitis and navicular disease, as its effects as a vasodilator are thought to increase circulation within the hoof to help counteract the problems associated with these conditions.

There are many veterinarians—and horsemen—who do not believe isoxsuprine to be effective. Its use is therefore rather controversial within the veterinary field.

Isoxsuprine may increase the animal's heart rate, cause changes in blood pressure, and irritate the GI tract. It should therefore be used with caution if combined with other drugs that affect blood pressure, such as sedatives and anesthetic drugs. Because it is a vasodilator, it should not be used in horses that are bleeding, or in mares following foaling.