I agree with Maximo, you have to stay on top of mats, they really don't get better on their own, and must be removed before a bath. I found that working in a little Cowboy Magic Detangler before the bath worked with Joey, but he only had a few minor mats under his arms due to wearing clothes, your situation sounds much worse. You say you brush daily, but remember you have to finish off with a comb that's placed next to the skin to make sure that there is not tangles, a tangle can turn into a mat very easily. When you say you are brushing daily it sounds like you are leaving some mats in? I would take him to a groomer and expect to pay a higher fee, due to all the matting, and get their advice on whether shaving is a necessary. Some cotton coated yorkies really do better in short hair, and we found a really cute for Joey with shaved body hair and longer leg hair, he looks fancy but it's so easy to care for.
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