What is the ruling on setting hunting dogs upon a restrained deer, whether for hunting or for training?

Releasing a hunting dog on a tethered gazelle is forbidden, as it is a form of खेल (عبث), harm (أذى), and torture (تعذيب) to the animal. "Patience with animals" (صبر البهائم) - which is restraining them alive to be killed by shooting - has been prohibited because it is a form of torture and destruction of their lives. As for inciting animals against each other (التحريش بين البهائم), it is forbidden because it is foolishness and leads to harming or destroying the animal without a legitimate purpose. However, if releasing a hunting dog on a gazelle is for the purpose of training and teaching it, then it is permissible.