Can food be too high in protein?

[Furbaby's Mommie]

Shoni is an MVD dog, high bile acids, but has always had normal liver enzymes, like ALT. He gets a variety of things to eat, like a little banana, cheerios, yogurt, and I add in a different canned food every couple of weeks---but his regular standard every day is Karma dry only 1/4 c., and about 1/4 c. of California Natural Lamb & Rice canned. It happens to be the only 2 things he will eat consistently. On both dry and canned I add 1/4 tsp. of Missing Link Plus, and a probiotic. He gets fed in the morning and at night, but almost always eats only once a day, and that is late before bed. (It's like "O.K., if I have to!" just before turning in.)

Even eating as little as he does, now that he is almost 2 he is a little fleshy. Padded ribs. I say he is a 6 lb. dog who weighs almost 7 lb.