Anyone can train a dog to pass the PAT test that is the law, you do not need a trainer though its recommended.
There is a fallacy going around that a dog has to be re-certified every year, this is not the case at all.
The Council Laws (in NSW at least) state that your average Rover Fido or Muffin (pets) are classified as companion dogs. Therefore the terms “assistance” and “therapy” dogs now prevail to differentiate. This may vary a bit between States so don’t take this as gospel.
An “assistance” dog can be there simply to keep you emotionally on an even keel. The term therapy dog is a little confusing, much the same as an assistance dog.
You do not need to do an 18 month course to have a dog trained and certified, and only the training people can certify the dog. Queensland laws are such that an independent person must certify the dog. The person that trained the dog cannot certify it.
There is no law that says a dog must wear an assistance type jacket – it just makes life easier. An identifiable lead, harness or collar will suffice.
The Civil Aviation Authority in Australia and airlines have their own set of rules regarding carriage of assistance animals on aircraft. There is one reported case where a woman did all the right things prior to booking only to get refused at check in by QANTAS. Best of British with this one.
Any dog can be an assistance dog though some breeds are better than others.
You do not have to purchase a pre-trained dog, your own dog will do if it is up to the task.
Working dogs, Labradors, Beagles generally (and I say generally) make the best assistance dogs though your own Bitza may very well be OK.
I can certify a dog trained by anybody anywhere, the PAT test is common core.
There are lots of different types of therapy dogs for all sorts of syndromes. A qualified trainer is the best option here. Its seriously specific training. This is on top of the Public Access Test and may be expensive.
Beagles properly trained can detect cancer with a 97% accuracy rate BEFORE medical science can.
There will no doubt be more as time goes by….