Then comb through with a metal dog comb to make sure all the mats are out. (wy-os.net)
A metal, professional - quality dog comb with fine and medium spacing for the teeth is a necessity. (akc.org)
Dog Comb for Removes Tangles and Knots - Cat Comb for Removing Matted Fur - Grooming Tool with Stainless Steel Teeth and Non-Slip Grip Handle - Best Pet Hair Comb for Home Grooming Kit - Ebook Guide (amazon.com)