tripe allergy - any alternatives?

we use the 'trial and error' method to find out what foods Mambo is allergic to and now we can definitely say that it is beef and unfortunately tripe as well, it actually caused more trouble than beef (worse ear scratching, paw licking ect.)
he seems to be just fine on rabbit and rather good on chicken... we will try fish and lamb as well later on, but now we switched him to rabbit again because he reacted so badly to tripe that we need to wait until his ears get better before we will test anything new

we feed raw, and I'm aware that you need to feed your dog tripe to make sure it gets all the nutrients etc. Is there any alternative, anything else we can give him to substitute tripe?
we give him some vitamin + probiotic supplement but I don't think it's enough...

Tripe is usually used as an offal. If you're not feeding any other offal, you need to start now. Just a couple of kidneys or some liver here & there. Not whole meals of it cause that's too rich.

thank's for the advice Caryll! (bit late... )

we did some research and checked local shops, luckily waitrose sells chicken livers (already frozen and cheap!) and that's what we're giving Mambo.

chicken is good for him and it all seems to be just fine