All dogs, even short-haired dogs, need to be brushed from time to time. Small breeds with coats that continue to grow long present much bigger grooming issues, especially those whose owners choose to keep their coats long.
Not all mats are the same. Small matted dog hair can happen every day because your long-haired dog keeps shedding dead hair. This process of shedding is not like the breeds that leave hair all over your house. Rather, a long-haired dog sheds his hair in a coat that causes small mats to form.
As new hairs grow, mats may appear very close to the skin. Scissors may be used to cut the skin, so you will need to use other matt hair tools.
Shih Tzu dogs have very thick coats made up of two layers: a thick outer coat and a soft inner coat.
Brushing the outer coat will make the dog look good, but it may not fix all the mats. Sometimes the only way to ensure that the dog has been thoroughly brushed through the entire body with a metal comb.