My Pixie is 7 months old and i hardly ever put clothes on her now because of this, maybe a coat/sweater when going out, she even gets matted when wearing her puppia harness! I always brush her before and after wearing clothing and her harness, someone told me to line her clothing with silk?
I'm not sure what the answer is to this, i'm thinking it's just the type of coat she has and that i'll just have to accept it!
When i mentioned getting a harness for pixie to my breeder she said she "wasn't in favour of harnesses as they ruin the coat" and she gave me a slip lead, like the ones used in the show ring, now i know what she meant!