Some kind of beef variety would be nice.
We have roo biscuits available here but htat's an Australian thing I believe.
Oh, and a low fat or possibly vegetarian variety might also be a good choice.

I would like to see a biscuit that incorporates calcium and vitamins suitable for puppies too.

*hugs*

Ah just thought of another one you might like to try. A sweetish biscuit with carob and honey in it. *hugs*

Have you done a grain free biscuit yet? If so, maybe something to incorporate more omega 3s and 6s, something fish based maybe?