I'm going to disagree with you on that. Businesses have been absolutely crucified in the press and with the general public when a story about denying a service dog has come out. Once the bad press is out, there's no taking it back Someone who is selfish and jerky enough to fake a service dog would most likely be that type of person screaming to anyone who would listen about their rights. That could easily and quickly destroy a small business.
Businesses have been crucified for not knowing a more than 20 year old law. I have researched and read all kinds of service dog stories over the last 2 1/2 years in preparation for when we got our service dog in May. The business either says no comment or apologizes for employee not knowing the law. Not once have I seen a business say "the dog was acting aggressively so under the ADA we exercised our right to deny it entry or asked to have it removed".
I believe it is in this thread about the lady with a yorkie yelling and screaming because she was either being asked to remove it or not allowed in, why wasn't this a big deal? A company like Disney denying a service dog that would be a huge news story, but it wasn't because they were right.
By this same token, anyone can print up a fake drivers license and go drink in bars underage. Sure they could try, but when the state issues a certificate they make it hard to copy.
Make the service animal status an endorsement on the pet's license. The state can accept documentation from knows service dog trainers (like leaderdogs, paws, CCI, etc...) and for unknown ones require a demonstration of basic self control to a test facility run by one of these known service dog breeders. The law could cap the price of this test to something reasonable.
As for business owner rights, you might be surprised. There is a clause that says if having the dog with you 'fundamentally alters' the nature of the business they can ask you to leave the dog outside. So far, examples of this include a dog barking while in a movie theater. ADA guidelines and FAQ actually say that a barking dog cannot be asked to leave a restaurant.
I was told by a restaurant owner that a dog with some horrible odor and visible fleas could not be asked to leave under ADA guidelines. On an airline I watched someone with asthma nearly die because the service-chihuahua she was seated behind had more right to be there than she did.
As it stands, the only recourse is to kick the service dog and its owner out and risk a lawsuit. During the lawsuit the owner of the service dog will have to prove that they are disabled and that the dog is necessary for that disability. All I'm saying is that if the law can require them to prove this AFTER they take it out into the public, maybe it's not such a bad idea that they do this BEFORE they take it out into crowds of people.
No, anyone can print up a license to carry their cell phone. There are no fake ones because there are no real ones, they aren't needed.
Go back and look at my post #38 for why certification wouldn't help. Your implementation of it has problems as well. Hard to copy equals more expensive. "Known trainers" who decides? There is no current standard certifying trainers, so first you have to certify the ones that will be issuing the dog's certification. Demonstration at one of your "approved trainers" who pays for the travel costs? How long is certification good for? How often do they need to go through the hassle and expense? Service dogs are not robots, they are not set it and forget it, it is constant consistent training, the best trained dog will behave badly if it's handler does not enforce the training. Then you have a poorly behaving certified dog. Cap the fee at something reasonable, who pays for the rest?
Restaurant owner is wrong, visible fleas is a valid reason to deny access, and horrible odor in a restaurant could be a fundamental alteration it would just be hard to quantify. The chihuahua didn't have more right, it doesn't have any right, the person with the disability has the same right to be there, accompanied by the dog. That person could have asked to be moved farther away from the dog. The reason allergies is generally not a valid reason is because it is not the dog the person is allergic to it is the hair, dander, and saliva. Refuse the dog and the person, as well as most pet owners, still has hair, dander, and saliva on their clothes.
Your last paragraph is where I have the biggest issue. Yes if filing a complaint the person will have to show they are disabled and that the dog does tasks to assist them, but it is their choice. They can choose to file or not to file. Also and really the bigger issue is that is all they have to prove, disabled and tasks. They do not have to take the judge with them and do a public access test, but that is the whole reason you want certification, to prove their ability to be in public not their tasks. You said they have to prove it after so why not before, but they don't have to prove public access after. They have to prove public access every minute they are in public, if they fail they SHOULD be asked to leave.