it would not be good ettiquite and might royally make some people mad if you represented him as a therapy dog and he was not certified. it's like wearing a police uniform, it's not honest and in many places illegal and subject to serious prosection. if he's not certified then he's not a therapy dog. meant kindly.
not to sound stodgy but many people in the service dog and therapy dog part of society work very hard to be accepted into institutions and businesses and go through rigorous training to assure the public that their dogs are not only safe but respectable members of society and have earned, through impeccable and extensive training, the right to be there. they are considered ambassadors of service and therapy dog community and they are where the public gets their perception of how these dogs comport themselves.
people with service and therapy dogs are subject to GROWING of grief over "fake" dogs because more and more people are being purposely deceitful and saying their dog is an emotional support dog etc. so they can take their uncertified dogs into businesses and facilities that do not allow dogs. Not only is this dishonest it creates a huge amount of hassle and discrimination toward people that have a legitimate right and need to take their dogs into facilities.
buying or having ur dog wear any working dog vests, badges, or id cards is not only warned against on all of the websites that sell these items but could earn you a ban from buying and some legal prosecution. ADA (Americans with Disabilities Act not sure of other like international laws names) laws and violations are a hot topic these days where partly because most people have a blurred line between service and therapy dogs legal rights. Therapy dogs are not allowed free access to all places humans are as service dogs are.
Should you be questioned or asked for credentials you are required to carry them on you and your dog at all times. Having anything other than genuine id may get you in a lot of trouble. especially if there is an incident involving ur dog or you are discovered misrepresenting your dog. the business may decide to really crack down on all animals and make life harder for people that already have it much harder than the rest of society or they may ban therapy dogs and many people lose the benefit.
Wal-Mart is having a huge brew-ha-ha right now over some people that lied about their dogs being certified and Wal-Mart started refusing entry to service dogs and hassling people that were disabled. they actually issued a statement asking for clarification on what exactly a service dog is and that they were refusing entry because so many people were claiming their animals were emotional support/therapy dogs. so not only has the disabled community rallied against Wal-Mart, jobs have been lost at Wal-Mart, and disabled customers are seriously angry and engaging in litigation as they should and have every right to do.
Mostly this happened because people don't stop to think about how their momentary convenience affects thousands and thousands of disabled people. I just this week got a disabled placard for my car for the first time though i needed it years ago i felt i could get by without so i did. although i don't "look" disabled most of the time I've had a few exchanges already in parking lots because many people abuse the handicap parking system. here i am getting out of my car without a cane or wheel chair and i get glared at a called names "look at that b*tch she isn't crippled," clearly audible, when i actually have to work really hard at not being stared at because of my disability. I'm lucky i can pass for "normal" more than some can. Often I exhaust myself doing so because i don't like being stared at or pitied.
so don't misuse the therapy dog vests, equipment, id, and other things because you will make life harder for those that come behind and beside you. 10 years ago service dogs were not often discriminated against. now it's not a rare thing to be interrogated very unkindly when entering a business and even having police called because of past abuses.
if you have an agreement with a facility to bring an uncertified animal into a facility then they should in no way be wearing equipment reserved for or resembling certified animals. It's like wearing a security uniform and having people assume you have some authority when you do not. I know it's not something a lot of people think about until they are given a perspective from inside so I respectfully offer it.
just google service therapy dog ADA litigation if you want to see how many cases there are pending and what a mess it is. after overcoming resistance to the ADA when it was passed; disabled and therapy dog handlers now must overcome the ever broadening spectrum of uncertified pet animals that are flooding into society as carrying purse dogs and other animals has gotten trendy.
hope i didn't come across as unkind (did not mean to) but those that wear the certifications should earn them and others should not take away from their meaning by diluting that hard-earned distinction. you have a lot to contribute and much good to do. i did not mean to imply u weren't honest, just did not know hence u asked. that is nice.

i've gotten a lot of info in a short time so i share. there are those extremists that want only 1 org to certify and only for the blind. so all kids of extremes and situations. i just wish u trouble free rewards 4 ur work and success however you proceed. :msnwink: