She is literally scratching 80% of the time, I've read that it could be a zinc deficiency or a food allergy but I have also read that it is bad to be changing diets with puppies. There's so much information out there and half of it is contradictory. I have a vet appointment next week but I could really use some advice on how to help her. My other pup is terrier breed and has never had anything like this.

Thanks in advance!!

There is another alternative (and really, probably more), have you considered 'pests' fleas, mites, etc? Possibly, also, fungal issues?

Clean bill of health from the vet when I had her at the vet a few weeks ago. They said to change her food and come back if it didn't work.

Okay, what were you feeding her, have you changed her food and if so to what.

Please fill out that part of your profile that gives a location, you'd be surprised what we can guess if we have an idea where you are. It doesn't have to be exact but city / county, state will help. I live in the desert of southwest Texas and while a lot of things work the same, dog food tends to be regional and things our dogs can catch (in both senses of the word) are a lot different. (( Dogs catch colds or dogs catch rabbits ))

Hi my pup Aspen has had itchy skin issues her whole life. We recently saw an amazing g dog dermatologist and my girl got an injection of Cytopint. We gave her the (lower) European dose and she is now itch free! First dose lasted 8 weeks.
Also watch diet my doggy dermatologist suggests pork for dogs. No chicken and not a lot of beef. All pups are different thou.
Try the cytopoint or look into it - it helped a lot. Good luck
Watch zinc levels - too much can be fatal.

Getting rid of all sources of chicken was the best diet-related decision I ever made. Eliminated itching and icky-tummy problems. Good luck!!