If you need fat with your venison, you may try adding beef fat. I find that pork fat is quite expensive here, being sold at the same price as sausage. This make sense because it all would be going into the sausage anyway and the butcher does not wish to sell it at a loss.

Beef fat (trimmings) is usually thrown away so the meat counter at our local grocery sells it for a dollar a pound or less. The resulting hamburger, when it is mixed with venison, looks and tastes like regular beef burger.

Bob