Good for you going raw! (or rather, good for your doggies
I'll answer your questions to the best of my abilities. I'm by no means an expert, but I have been feeding my three raw for over a year and they're all healthy and happy
Feeding amounts - you should feed your adult dog around 2% of it's ideal bodyweight per day, you may need to feed a bit more for a very active dog, or a bit less for a lazy pupper. Puppies eat up to 10% of their body weight. Watch your dog's waistline (check ribs, waist, and neck), and adjust amounts accordingly.
Ratios - Everything I've read says 60% RMB, 20% meat, offal and fish, and 20% veggies (and grain if you feed grain - I don't). I find that's not enough meat or bone for my dogs. I feed about 70% RMB, 20% meat, offal, and fish, and 10% veggies. I used to be really anal and measure everything out. Now I just give them bones a few days in a row, and then feed them mash (veggies and meat or whatever) for a day or two. They get offal or fish whenever I think of it.
You can feed too much offal (liver, heart, etc.), as it's very rich and high in minerals. It's not recommended to feed offal more than once per week.
Egg shells are really high in calcium, and are a bone alternative. I don't feed them that often, as I feed bone daily and don't want to bugger up the calcium/phosphorus ratio. However, if you're giving them an egg, it should be fine to just give them the shell too. Just watch your dog doesn't get too constipated.
I would definitely add veggies, but this is debateable. Some people insist dogs are strict carnivores and don't need vegetables. I think they do need them, but again I'm not an expert. Wolves and wild dogs are eating wild game which has eaten a balanced, varied diet, and contains all sorts of vitamins and minerals. My dogs are eating domestic meat, which has been raised on hay and grain, and certainly isn't as nutritionally complete as wild game. So I feed mine veggies. Plus, the fiber's good. I do not feed grains however, it's not needed IMO, and Gage is allergic to all grains. Plus grains = farts
I add plain yogurt for the bacteria in it, plus it's tasty and makes it easier to mix things together into a texture that is easily gobbled up rather than flicked all over the kitchen from a doggy tongue
I also add olive oil to my dog's food now and then. I wouldn't worry about the fat from yogurt, you're only adding a couple tablespoons a day, and the amount of fat in that is pretty small. I wouldn't bother with other types of dairy.
I'd be careful how much animal fat you're adding. Too much fat is bad for the pancreas. I just feed the fat that's already in the meat or in the skin that comes with that cut, and add a little here and there if they're coats are looking dry.
Tongue is a muscle, so should be fine.
You CAN feed too many bones if they're actually consuming them - they'll get fat
. Try giving them femurs as recreational bones - most dogs can't eat right through those (although Angel does sometimes). A good, strong knuckle bone will usually last a while as well.
The other things I add are apple cider vinegar, kelp, fish oil, ginger, and cayenne pepper. Apple cider vinegar contains 19 of 22 trace elements in exactly the right amount, kelp is rich in minerals, fish oil is good for skin, coat, and other stuff (I forget
), ginger is good for digestion, and cayenne is good for something too, I think maybe the immune system? Cayenne and apple cider vinegar both help speed up the metabolism and promote weight loss (they're in every diet pill out there). I feed my dogs regular ground beef as a meat source, which is high in fat, but they don't have any problems with pancreatitis or anything, largely I think because of the apple cider vinegar. My dogs are VERY lean, and never have any fat on them, just muscle.
I think I answered all your questions