
My golden likes having a carrot for a chewy treat. He likes fruit, apples and oranges, but not too much or you'll be cleaning her pants (no grapes or raisins, they're dangerous).

You could bake some treats without meat, like cheesy garlic chunks. 1 1/2 cups flour, 1 1/4 cups grated cheese, 14 g butter and a couple of garlic gloves. Mix it together, chill for 30 minutes then roll onto a floured surface. I just chop them into little squares and bake for 15 min. at 175 C. You'd have to work out how much protein was in the batch. I'm going to experiment with making marmite treats because he loves marmite toast. Anything smelly will be appreciated I'm sure. Maybe some flavoured rice cakes; peanut butter or cheddar.
I'm not sure about the phosphorous content of cheese though. Some dairy products are high in it. Looking at the site someone posted in reply to your question on the feeding board I would experiment with the ingredients listed as appropriate. Mixing rice flour with egg white, yoghurt and honey. Maybe try adding mashed veg such as butternut squash. If you can squash it in a pan and nuke it so it holds together I'd call it a dog treat. I make tuna cake with 400g tin of tuna, 3 eggs, 3 cups of flour and some yoghurt - just as an idea of wet to dry ratios.
It would be a good idea to have some special toys that only come out on walks too. So sometimes her reward is her favorite toy.