From experience working in a grooming salon, I would say 99% of the problem is that the dog has learned the salon is a place of pain. Take for instance a mini Poodle pup we saw at the salon fairly often....
Her owners never--and I do mean never
--brushed her. We first started seeing her as a pretty young pup, but she still had lots of fur. They insisted she be kept full length. Her first few visits, she was just a pup who hadn't been groomed often. A little crazy, but otherwise sweet. However, she had loooots of tangles(at those visits, her fur hadn't quite grown enough to really get bad mats). No matter how careful I was, brushing her out hurt. Period. The older she got, the longer her hair grew, the worse her tangles/mats got. She became vicious because she knew that every time she came to the groomer, she was going to be hurt. Not that we wanted to, by any means!
First we thought that maybe they were just ignorant. We showed them the right brushes to use, and how to use them, and how often to brush her. The next time she was just as bad as the time before. They didn't care and didn't try. After ALL of us attempting to help these people care for their dog, I'd had the last straw. I was not going to put this dog in more pain that she did not have to go through and certainly did not CHOOSE to go through. The salon manager and I decided to do what was best for the dog---regardless of how angry the owners would be. We shaved her down completely, got rid of all
of her awful mats--the first time in the first year of her life that she had EVER had any length taken off of her coat. Her owners, naturally, were furious and never returned. But this dog was becoming dangerous to us and herself, and we were not going to continue putting her in pain when the owners didn't give a darn about taking care of her.
Another dog we had was also very vicious...he was a Lhasa named Brownie. The first time he came in, we shaved a mat out of him that was LITERALLY the length and width of his body--one giant, Lhasa-sized mat. It was disgusting. The owner tried to tell us she'd been "out of town for the weekend, and his sitter didn't brush him." Let me tell you something, groomers are not stupid. It takes far longer than a weekend to get mats like that.
Soooo....your first hurdle will be getting him to enjoy grooming. A lot of this can be solved simply by getting rid of the tangles and mats so that brushing does not hurt him. When you take him to the groomer, do not be vain. Shave him down completely if
that's what it takes to get rid of all the mats. Doesn't matter if he doesn't look like the pretty, full-length Shih-Tzus. He'll feel much better.
A soft slicker brush
A wide-toothed comb
A mat breaker---***Ask the groomer to show you how to use this tool properly. Do not just attempt it yourself without knowing how to use it right.***
Now for the training...
How does he react when you just bring out a brush? Is he alarmed immediately, or just once you start brushing him? If he immediately goes into attack mode, or flees, or shows any signs of stress at the sight of the brush, then here's something you might try:
-Bring out the brush only at the best times of the day for him. This means mealtime, walk time, or when you bring out his favorite toy. You might also bring out the brush, sit it down, then just have a massage session.
So for example, bring out the brush, then immediately give him his meal.
Bring out the brush, then go for a walk.
Bring out the brush, then just sit it down and play with his favorite toy.
If you start doing this regularly, he'll begin to associate the brush with good things.
From there, you can work on getting him to like being brushed. Watch this video
--see how she reaches for the dog, but doesn't pet him, then clicks and rewards? You can do the very same thing, but with a brush instead. Reach towards him with the brush, click and reward. Work your way up until you can touch him with the brush, then maybe stroke him once with the brush, then more and more until you can brush him all over.
Do you have some kind of table or something elevated you can put him on once he is not aggressive with being brushed? This could be helpful too, as the groomers will most likely not be sitting in the floor or in a chair to groom him. If he has mats, do not do not do NOT wash him. Water will make these mats tighter, and soap/dirt/dander can get trapped in them and irritate his skin.
Be picky when choosing a groomer. If he's that difficult(as I assume he is if his last groomer refused to see him again), specifically ask for an experienced, patient groomer, and ask about the SLOWEST
day and time for an appointment. This way, the groomer will not be rushed to finish him or other dogs and can take their time. Let them know that you are working with him, and explain what you've been doing in detail so they can also incorporate these methods if need be.
When you find a salon you are happy with, try taking him their randomly, not for grooming. Go to the salon, but maybe just play with him or even brush him once he's advanced enough to tolerate grooming willingly at home with no aggression. (At the salon, he will probably regress--this is an unhappy place for him, so brushing at home is not as pleasing as brushing there. You'll probably have to go back a few steps.) What do the groomers wear? Smocks? Scrubs? I did have some dogs that were actually much better behaved if my smock wasn't on. The connection wasn't completely with grooming, but more so with the evil smock-wearers. Without the smock, I just looked like a potential friend in normal clothes...not the mean person who caused them pain. If he does have a negative association with smock/scrub wearers, or whatever else they might wear, you might get one for yourself and wear it for walks, feeding, play, etc as described before.
Hope this is helpful. Also, understand that good groomers never intend to hurt a dog when trying to brush out a mat. Mats hurt, period, regardless of how you brush them out. So the best way to avoid that is to brush often enough to not have mats in the first place. Once your new groomer shaves them out, get to work on a regular brushing schedule. And brush everywhere
so you are sure you're doing everything you can to avoid mats. (With really long haired dogs, mats can form easily behind the ears, in the armpits, on the face, belly, hindquarters......but they can form anywhere if not brushed enough.)
Hope this helps!!! Good luck, be patient, and be careful.
Hamlet is fortunate to have someone like you to take care of his grooming issues!