Are you you using conditioner on him? a detangling spray?
I have one of these for tough matts. It cuts through the matt. You need to be careful not to hurt your dog when using this.
Bernina Original Dematting Comb | PetEdge.com Master Grooming Tools Ergonomic Dematting Tools | PetEdge.com
Some say the combs with rotating pins work well but i personally don't care for them...or at least not the one i bought.
