Hi Nadine-
The main thing to be looking for in a large breed puppy food is an appropriate calcium/phosphorus ratio and an appropriate calcium/calorie ratio. Dr. Mike has a nicely written article with a calculator attacted that will tell you if the food you choose is appropriate for a large breed.
/best-dog-foods/best-large-breed-puppy-food/
I don’t know what your reasoning for staying away from carbs were but dogs can very easily digest and utilize foods with up to 50% carbs.
If you want a good Dane food I would recommend Precise Holistic Complete Large & Giant Breed Puppy. It was formulated by an ex-Great Dane breeder. My boyfriends brother used it for his Dane and he grew perfectly. It is not grain free. I also personally have a dog that can not eat grain free foods or he gets sick, so I avoid them like the plague.
