Doginlaw-
I’m not sure how adding a bit of protein and a splash of water to a high calorie food will help with weight loss? But, the fish and potato formula that Tyrionthebiscuit mentioned is only 360 calories per cup. It might be worth checking out!
In addition, I also feed Purina Pro Plan, Purina One, Eagle Pack, Authority and Victor weight management kibble with success. Some of these may not have potatoes if you are trying to avoid them. My dogs do fine with them.
Again, I think weight loss would really benefit your pup.
Best wishes!
