Most of the human pin/vent brushes I've seen have the little balls on the tips. The tips will damage a yorkie's coat, it's better to use a pin brush with no tips. Chris Christensen, #1 All Systems and Greyhound are 3 different brands that offer the tipless pin brushes. All 3 brands work about the same, IMO.
Btw, puppy matting is normal and is just difficult at times to deal with. The best way I found to keep the matting to a minimum is to brush/comb a puppy everyday. This also helps get them accustomed to the grooming process, that will be life-long.
__________________  ~Ruby, Reno, Razz, & Jack~ |