Does my westie puppy have food allergies?

It used to be that vets didn't consider gastrointestinal symptoms indicative of a true allergy.  Rather, gastro symptoms were called food sensitivities or intolerances.  I don't know whether the thinking on that has changed or not.  What matters is that they're treated exactly the same way -- avoiding the offending food(s).

Now . . . what you're describing sounds extreme to me.  I think in your shoes, with such a young puppy, I'd want to find another vet who'd be more willing to do some detective work to rule out possible causes other than food. 

At the very least I would be extremely vigilant over the next couple of weeks in making sure that he gets nothing but the NB and see how he does.  NB is a good food, no worries about him not getting adequate nutrition if he's able to eat it w/o developing diarrhea.  Another option would be to home cook for him.  We can provide more info on some sources who will work with you to prepare a properly balanced diet for his individual needs if you're interested in that.

Thanks for your answer, Im looking into finding a second opinion from a different vet. I hope this gets solved.

Glad you are getting a 2nd opinion.

It's possible she is grain intolerant.  My sister has a westie with a very sensitive tummy and she has been feeding California Natural with success.  She is keeping a close eye on the ingredients since the P&G buyout though.

If you are interested in cooking for her, there are several good books out there.

I also reeeeeallly like The Honest Kitchen foods.  

Let us know what the vet says!

Also, cat food is generally pretty 'rich' and could probably do that to his tummy.

Westies, as a breed, tend to have many allergy issues AND skin issues as well as digestive issues.  Resist the urge to switch foods constantly -- you can actually CAUSE allergies/intolerances that way. 

I'd second finding a different vet -- this is a pup and they can be prone to parasites (their body just isn't mature enough TO ward anything off yet and when they are growing fast the immune system isn't functioning as it should either).  So I would hope a vet was keeping ON the fecal (not just a float, but a smear and really LOOK at it)

Thanks for all the answers, much appreciated. The vet said for me to take another stool sample and he wil send it to another lab where they can do more exdtensive testing, he mentioned testing for Giardia. I will keep you updated. 

Good!  Giardia is a definite possibility.

Now Im not convinced he has food allergies/intolerance. Well I was not looking he ate a huge plate of lasagna. I thought oh oh here we go. All the noodles and spices will for sure upset and stomach. I waited for the storm to hit and then nothing, not even a rumbly stomach.  This got me thinking that it might not be a food intolerence.  Hmmm....

I agree with some of the other posts. I would definitely find another vet. Ask people you know for a referral. I've always had wonderful vets but since moving to Florida I've tried 8. They seem to be after the money and only want to run unnecessary tests and still not always giving me satisfactory answers.

Dogs have quite sensitive stomachs so it's not helpful to keep switching their food. When you do change foods you're supposed to do it over the course of a couple of weeks by mixing a little new into the old. I've heard great stories from people who started preparing their own foods and it really helped their dogs.

Another thing to consider is bad breeding. Do you know if the breeder was reputable? A friend of mine got a puppy from a breeder many years ago and he was sick from day one. She loved him so she kept him but she had to be very vigilant with his diet or he would keep getting sick.

Good luck and don't give up!