Collars aren't an issue if the daily brushing routine is kept up. I have yet to find one matt on Kaji's neck hair, and he wears collars 24/7. I brush him in the morning and at night, which is a must anyway in my book.
I do however sometimes struggle with harnesses. I use them of course, but the wrong kind chaffe my little man's belly and arm pitts and matt up his belly hair real bad.
