He is definitely underweight...but its very hard from the angle to tell how underweight. At any rate with raw...you can start feeding it right away as is...but I would slowly add it to whatever dry food he's had (if he's been getting anything...). I would give him dry food for at least a week or so..and then start introducing the raw...maybe start him off with a chicken wing section for a couple days, then do 2, then give him something a little bigger like a turkey neck or something for a couple days...etc etc. I would add organs last. He may get a little upset tummy, but if you do it slow it shouldn't be too bad....or he may have no problems at all. My dog had no trouble whatsoever transitioning to raw....although he was on a good kibble (Natural Ultramix). If you want to try to be even more sure that he won't have troubles you could try transitioning him to a higher quality kibble before going to raw, as it will put the nutrient levels closer to what is in raw. Nature's Variety would be a good one to do that with (they even do a freeze dried raw coating on their kibble!).
