Here in the USA, disabled people are allowed to train their own service dog to assist them with their disability. However, just because you CAN do something doesn't necessarily mean that you SHOULD. Utilizing a service dog is becoming very popular. However it is not necessarily the best way to mitigate every disability.
It is my personal belief that if you have not trained multiple dogs through basic to advanced obedience and if you don't have the knowledge to deal with basic problem behaviors and potty training, then you don't belong training your own service dog, especially not training your own service dog without the assistance of a qualified professional dog trainer. That trainer doesn't have to necessarily be experienced in service dog training, but that is a huge bonus. You should also be able to afford the minimum necessities of housing, feeding, vet care, emergency vet care, gear, training classes, etc. without having to fundraise for those basic necessities. If you can't afford even those basic things, then you really likely can't afford a dog period.
I am a professional pet dog trainer with years of experience training dogs for myself and my clients. I am also disabled and have now successfully trained my second (and third) disability assistance service dog(s) for myself. Owner training your own service dog is NOT simple or easy or even necessarily inexpensive. It takes time, energy, and most importantly knowledge of dogs and dog training. Those of us who train our own service dogs to high standards spend hundreds if not thousands of hours training our dogs in their obedience, disability related tasks, and public access skills (which means training in coping with the vast stresses and new experiences of working out in public places), which can take anywhere from 6 months to 2 years depending on the age of the dog. This is not easy and is not something to be undertaken lightly.
http://www.iaadp.org/iaadp-minimum-training-standards-for-public-access.html
Before I began training my first service dog I spent months researching about service dogs, speaking with service dog handlers and trainers, joined a yahoo group for service dog owner trainers. Even with all my experience I still felt slightly overwhelmed at the prospect of training a dog to assist me and be able to function well and assist me out in public. I did extensive online research about training and recommended minimum training standards, public access tests to help determine if a dog is prepared for working out in public, service dog laws, service dog etiquette, etc. Now I know everyone isn't as detail oriented as I am. But it seems that nowadays everyone is deciding on a whim to just go out and get a dog to train as their own service dog, often with very negative results. Every time a dog is labeled a service dog and misbehaves out in public it gives the public a bad representation of service dogs. This makes things much more difficult for service dog handlers that have put in the time and effort to train their service dogs to a high standard.
In order to be able to be accompanied by a service dog, the handler must be legally considered disabled, which means having substantial impairment to one or more life functions, including but not limited to caring for oneself, walking, seeing, hearing, thinking, working, eating, sleeping, etc. No disability, no service dog.
And because I HAVE to say it, the ADA law defines a service dog as a dog TRAINED to perform tasks or work that mitigates the handler's disability. Emotional support and comfort by the mere presence of the dog is NOT considered task trained and such dogs are not legally considered service dogs and their handlers do NOT have the right to have them in places where dogs aren't generally permitted. The law states a service dog must be housebroken, under the control of the handler, and not present a health or safety risk to the general public (generally interpreted as not being excessively dirty and not behaving aggressively or dangerously).
http://www.ada.gov/service_animals_2010.htm
Also, there is NO legally recognized or required certification, registration, and/or identification of service dogs in the USA. Places of public accommodation are NOT allowed to ask for or require any form of documentation for a service dog or require specific types of gear for the service dog to wear. When it is not readily apparent if a dog is a service dog, a place of public accommodation may legally ask two questions. Is this a dog required because of a disability? What tasks or work is the service dog trained to perform. No other questions or inquiries into the handler's disability or demonstration of tasks may be asked for or required.
Also, VERY importantly, a place of public accommodation has the LEGAL right to ask for a service dog to be REMOVED if the service dog is out of control and the handler does not take action to effectively regain control, if the dog is not housebroken (as in goes potty in a business), and/or behaves dangerously/aggressively or is excessively dirty. So just because you say your dog is a service dog DOES NOT give you carte blanche access.
Choosing a suitable dog for a service dog prospect can be quite difficult. Not every dog is suited to being a service dog. Service dogs must have extremely stable temperaments and be absolutely structurally sound. It's not as simple as "get yourself over to the shelter and rescue a dog." Great service dogs CAN come from shelters and rescues. I know, my first service dog was from a shelter. But choosing a prospect takes time and proper temperament and structural evaluation. When I was looking for my second service dog prospect, after my first service dog retired due to arthritis, I looked in shelters and rescues in SIX states for nearly a YEAR and never even saw a dog I thought I should go and evaluate. I ended up getting an amazing young adult male dog from a breeder I've known for over 20 years now. So the process of even finding an appropriate service dog prospect can take a long time and should not be rushed.
And as for choosing the breed of your prospective service dog, especially for a first time service dog trainer and handler, there's a reason the big programs use Labradors and Golden Retrievers. While you may want a special breed, if you don't have extensive experience with a specific breed, do yourself a favor and choose a breed known for success in service dog work, like a Lab or a Golden. While I know Labs and Goldens don't work for everyone, choosing breeds not normally known for success with service dog work is starting from behind in many cases. And while just about any breed MAY be able to do service dog work, it doesn't necessarily mean that they SHOULD or that most individuals of that breed should or can do the work. You also need to consider breed specific issues regarding housing, BSL (right or wrong, it exists), public perception, etc.
And a service dog may or may not be the most appropriate way for you to mitigate your disability. Being accompanied by a service dog is a lot like having to take a toddler everywhere. You have to watch out for them, make sure their needs are met, make sure they stay safe, etc. Service dogs attract a LOT of attention from the general public. People interrupt you, ask invasive personal questions, distract your service dog while they are working, interfere with your service dog while they are working by petting, blocking, sending their children over to pet, allowing their children to pet, yell at, hit, or even jump on your service dog, etc. Some businesses will try to deny you access because of your service dog. All of these things you have to be prepared for and be able to cope with while being assisted by your service dog. Don't get me wrong, it's not all bad, but it can be depending on the location and the day. So you have to determine if the assistance you gain from a service dog outweighs the additional energy spent and stress of being assisted by a service dog. Is your disability such that you can handle the unwanted attention?
I personally wouldn't trade my service dog for anything other than being healthy and not needing them anymore. Being assisted by a service dog can be an incredible experience and partnership. But it is not something to be taken lightly and not something to undertake yourself without doing your research and being assisted by an experienced trainer.
If you'd like more information on service dogs and/or the service dog training process, please contact me at fcdogtraining@gmail.com
http://www.ada.gov/service_animals_2010.htm
http://www.iaadp.org/iaadp-minimum-training-standards-for-public-access.html