My information sources say that bleached (white) tripe can be fed to dogs, but the nutritional benefit is not as great as the fresh, very, very stinky, green tripe. In the USA, green tripe cannot be sold in a grocery store (because it is not fit for human consumption), but it can be bought from certain meat suppliers. Green tripe is sold as the entire stomach (without the stomach contents); ground up; or ground up with other muscle meat and/or organ meat. It is also sold canned. As everything canned, it is therefore cooked, and again not as nutritious as raw. It's nutritional benefits are very similar to that of muscle meat, however some think that there are enzymes in the raw version that a dog will not get any other way. Many raw fed dogs do not get tripe, and do very well without it.