Final answer:
Dropped hock and overflexion of fetlock are typically caused by damage to the peroneal nerve, a branch of the sciatic nerve.
Step-by-step explanation:
Dropped hock and overflexion of fetlock are symptoms typically associated with damage to the peroneal nerve (also known as the fibular nerve). The peroneal nerve is a branch of the sciatic nerve, which originates from the sacral plexus and is a systemic nerve that extends across the hip joint and gluteal region into the upper posterior leg. This nerve can cause such symptoms when it becomes inflamed or compressed under certain conditions, such as in the painful condition known as sciatica.