Editor’s note: To see the risks of getting a dud service dog, check out Annie’s companion story about so-called allergy-alert dogs who cost unsuspecting families thousands of dollars.

If you are considering paying for or obtaining a therapy dog, it may come as a shock to learn that no one is officially overseeing or regulating the trainers who train service dogs. Nor are there any existing enforceable requirements required to prove that the dog can do what the trainer says it can do. Because some service dogs can cost as much as $20,000, it pays to do your own intensive homework before you ever purchase a service dog. My advice: Examine in depth the service dog trainer’s credentials and experience — and insist on observing the service-dog-to-be in action in public places.

This can also save a lot of heartache for you or the child you purchased the dog for, before you ever bring the dog home and fall in love. Don’t be hoodwinked into buying a dud service dog.

If you are considering a service dog, here are important questions to ask of those who sell such animals:

1. What training have the dog trainers completed?

Get specific titles and certifications and ask what organizations they belong to, and then follow up and confirm it. It’s helpful for a detection dog trainer to have a specific background in training detection dogs, such as military detection dog or police detection dog training. The group Guide Dogs for the Blind has rigorous standards for their trainers.

2. Ask where the dog came from

Demand proof of lineage or written records indicating the dog’s background. Service dogs must not lunge, growl, or bark at strangers, and they must be calm in public. If someone attempts to sell you a service dog who lacks great manners, keep looking.

3. Educate yourself

Learn about the work service dogs do before you do any training at a facility with a new dog. A good place to start is the USDA’s National Detector Dog manual (PDF). Assistance Dogs International is a good place to gather information, such as their statement on Ethics for Dogs.

4. Insist that you get training with your dog in public places

This could be in crowds or near a school, since the dog will be doing much of his work in public venues. Hearing about an aggressive or unruly “service” dog who acts out in public is — unfortunately — all too common. A service dog must have good canine manners, just as it must be able to provide the service for which it was trained. At the very least, demand that your new service dog has passed the American Kennel Club’s Canine Good Citizen test.

5. Make sure the dog is certified

Perhaps most important, require that any dog you adopt or pay for as a service dog is certified not by the person you are purchasing the dog from but from a third party who is a qualified, certified dog trainer, and who has (provable) vast experience training the kind of service dog you are bringing home. Ask to see the certification process on video or in person and insure that the tester really is a third party with no self-interest in the organization.

Have you ever come across someone selling a dud service dog? Tell us your experience in the comments!