A new nostril support device for a horse comprises a shaped body for insertion into the nostril and an integral clip that retains the body in position by pressing on the outside of the nostril. The shape of the body is generally convex toward the clip and concave away from the clip. In a direction substantially parallel to the clip the body is substantially straight at the bottom of the concavity. Overall the body tapers to a substantially parabolic edge to ease insertion into a nostril.