finding what works for each dog....and not just lumping them in the same box. Mine have their own formulas, and quantities needed, but I've also found a balance that works for both. I do think Missy's metabolism is higher and she needs more fuel. She's not gaining wait on the extra she gets fed, so I love that. Chelsea's healthy skin and sensitive stomach food is also salmon and sweet potato!!! I'll have to check if either have taurine in them.