Good posts Frosty.

A sedentary house dog loses around 1200mL of water a day.
I wonder how its possible that the one dog i have in the house only eats 400 gram of raw food a day, which is 240 ML of water and dont drink anything from his bowl for weeks. This is a 45 lb dog, i don't which type of dog they used for the research but i figure its not a 250 lbs dog.

Yes, I'm adding 46oz of water to the dog's feed. Not long ago, I conditioned a 45lb dog, and he was getting 45 ounces of water, in his feed, everyday. After eating, he would be all filled with water, sure enough. He was also a very hard working dog who needed all the extra fluid given. When I would go out the next day to work the dog, he would usually weigh 46-47lbs. So, combined with the water and the feed and after him emptying out, he was only a lb or two above his show weight.
No questioning your experience but have you ever tried to give like 30oz of water for such a dog in training and check his skin count?