Is it permissible in Islamic law to transfer ownership of a mortgaged olive tree after a period of time without the consent of the second party, and is it permissible to mortgage an olive tree for a dog used to treat children as a sacrifice without consuming it?

The question is not entirely clear, but a mortgage is a permissible contract used for security in transactions. When the debt becomes due, the mortgagor is obligated to fulfill the payment. If he refuses or is absent, the ruler sells the mortgaged item. Any surplus from its price belongs to its owner, and if there remains a deficit, it is incumbent upon the mortgagor. It is not permissible for your father to take ownership of the mortgaged item except after the due date and the mortgagor's refusal to pay or his absence. The matter must be presented to the Sharia courts to sell the mortgaged item and give him his right.