Why is my American Staff/American pitbull terrier classified as an American Bulldog by the vet?

This sounds to me like a helpful and compassionate vet who is trying to protect the puppy and its future owners from rental problems, insurance problems and breed specific legislation

Vets are trained in medicine, not breed recognition. Your dog is a slightly mixed bully breed that the vet simply thinks looks like whatever he thinks an American bulldog looks like.

Added to the problem is that there are many bully mixes out there and because of pit bull discrimination, many shelters will call a bully mix a "lab mix." I'm sure you could insist the vet change your dog's breed designation, but it probably doesn't really matter. If the vet is stubborn, find pix of purebred Am staffs, pit bulls and American bulldogs and point out the difference.

If the vet still refuses, find another vet. This issue shouldn't be a big deal, and if it doesn't directly involve the health of the dog or the success of the vet business, well then the customer is always right, and you'd have to wonder what other more important issues the vet might be stubborn about.

Sounds like the owner of these dogs was very confused and/or trying to pull a scam.

The vet isn't a breed registry, and they may not have realized the pups weren't what the man was saying. If the owner at the time said "American Bulldog" that's what the vet wrote down.

I wouldn't worry about it too much - a vet's paperwork isn't the end all. My Aussie mix is listed as a "Rottweiler mix" at my local vet clinic - I noticed that one day and I have NO idea where that came from as it's very clear she's an Aussie mix and the vet knows so as well.

It sounds like perhaps it was a vet tech or vet who just assumed your dog was an American Bullldog. Next time you go there make sure to correct them so that they put down the proper information.

probably an insurance thing. because of bad breeders "Pit Bull" is frowned upon in a lot of areas. using different terms for a relatively similar dog will probably let the vet work with the dog without the insurance company freaking out.

No, they're just ignorant obviously. A mutt is a mutt, not a different breed.

Seriously? You vet is stupid. ABD's are purebred dogs