The abductor cruris caudalis muscle (abductor muscle of the thigh, previously called musculus tenuissimus in cats) is a straplike muscle only present in carnivores, that lies deep to the caudal edge of the biceps femoris muscle.
Origin: Arises by a long, flat tendon, which lies on the aponeurosis of the deep surface of the biceps femoris on the ventrocaudal edge of the sacrotuberous ligament near the ischial tuberosity.
Insertion: Crural fascia.
Action: With the caudal branch of the biceps femoris, it abducts the limb and flexes the stifle.
Nerve: Ischiatic nerve