I don't think that heart is considered an organ meat because I believe it falls under as a muscle. Green tripe is good for them, I believe that you can feed it to them maybe every other day or just mix it in with other meats but be careful on the amount you give them. I am not sure about the green tripe from a can though and how much you can feed them with that! But, if it's just green tripe then I assume that you can just feed it to them as I said.
This information I'm giving you is from what I have read and researched about raw feeding!
Mushu - 1/20/14