I had the same problem with my new puppy although she is just 9 weeks old and we have had her for a week and three days she would not eat the eukanuba puppy food that her breeder had her on. We went through all of the same stuff you are doing last week finally yesterday I got some samples of the natures variety praire Kibble the chicken and brown rice and she loved it I mixed it with her old food and she left the old kibble and picked out and eat the new kibble and she wanted more which I was afraid to give her I don't want to upset her digestive system. I know that you can go to the website
Nature's Variety and you can read all about the different food choices that they have.
I hope that you find something that your baby likes soon.
Good Luck
Tess