So. There is no one way to identify a service dog. There is no requirement to do so. There is no reason for any of us to expect or even want anyone to spend more money on anything to make us happier or to make us believe a dog (or miniature horse) is a service animal.
The "little poof dogs" are just as much service dogs as other dogs. The tiniest teacup applehead chihuahua (if such a combo exists) can be JUST as much a service dog as the most service-dog-looking service dog ever born and trained.
Your issue is the feet. That's where you should focus your rant. It is insulting to anyone with a little dog that can detect blood sugar changes or an oncoming epileptic seizure, or who has been trained to *do a task* for the human-with-a-disability, when you talk about "little poof dogs".
What you COULD do is bring brochures about paw protectors with you, and sweetly kindly decently give them to people with service dogs that you're worried about.
Sigh.
If someone sits and tells you "this isn't a service dog, I just want my dog with me", then go find someone in authority.
If no one is saying that, then just assume the dog is a service dog and move on with your life after handing them the paw protector brochure.