I've given pork hocks and know a lot of other raw feeders that do too. I've heard they are really great for cleaning teeth, the skin on the outside gives them something to chew through and is also another fantastic teeth cleaner. I wouldn't trim anything off them, though! Pork is very fatty, but because raw fed dogs don't eat carbs (grains, sugar, ect) their bodies don't store fat like it would if they were eating those kind of carbs. It's like if we were to go on a no carb diet, you can eat as much protein and fat as you want, and won't gain weight (it's a horrible diet, but I've done it and lost pounds very quickly before a trip to Jamaica). So as long as it isn't excessive, fat isn't a bad thing with feeding raw!