One of my dogs had an upset tum a few weeks back. To clear it up we fed chicken and rice. Did the trick but....

We put all the dogs on the chicken and rice otherwise there would have been stealing of food from each other. Although we transitioned them back onto their normal dry food, the first meal with just dry, all three looked at me as if to say "Silly Woman, where's the good stuff? You made us sit for this rubbish?"

I gave them ten minutes (each ate a few pieces, but not much) then took up the bowls. Next meal, they again just picked at it. Again I took their bowls away. The next meal, they got their appetite back and cleared the lot.

I do normally mix their dry with a little 'wet' food in the evening. I didn't want to reintroduce the wet too quickly as , although a good food (Nature Diet), I worried it might be a bit rich for the old boy's tum so soon after being poorly. Hence the 'battle of wills'. But if it helps your puppy to eat, maybe try adding a spoon or two of good wet food to the dry biscuits.