Hi & Welcome to YT! So glad u found the site. I dealt with this over the weekend & have been working diligently to get them out. Just mainly on her back end & legs also. She went to the groomers on Sat & thank goodness they got out the rest. She is a good friend.
One of the things that work for me is if you can't brush or comb out the mat, take small scissors & cut into the middle of the mat. Then with yr fingers work on one side by gently pulling & working it out to be able to brush. I also read on YT about using corn starch. I tried it once & it did work really well. Using a small amt on each mat to work out with yr fingers.
Hope all goes well!