I'm not a fan of puppy rawhide chews. There often isn't much quality control in them and if you buy them loose (not packaged) you cannot see what country they are coming from. Did you know the light/white coloured ones get that way because they have been bleached? Scary. With more and more products coming from China, a country with very different quality control than North America, I think all dog owners have to really read labels and be diligent, not only with foods but even with things like toys, bedding, etc.
Make sure your little one continues to drink well. I have to say that I would do a vet visit. A change in water can cause problems - our breeders helped us with this by providing us with a huge jug of the water Kipawa had been drinking. We introduced Kipawa to our local water by slowly mixing it with the breeder's water. Those young tummies can be very sensitive, especially with a combination of new food/food items and all of the other new happenings they are experiencing.
Please keep us posted.