Supraorbital (frontal) nerve block, horse

Needle placement for a supraorbital (frontal) nerve block in a horse. A 25-gauge, 1.6-cm (5/8-inch) needle should be used. The supraorbital foramen is palpated by placing the thumb at the medial canthus and ring finger on the lateral canthus (using the left hand on the right eye, and vice versa). With the hand in this position, the index finger is dropped into the foramen, which is palpable as a small depression in the bone. Local anesthesia is provided by subcutaneous injection of 1 mL of lidocaine over the foramen. Injection directly into the nerve should be avoided because it can be painful and can damage the nerve.