That degree of matting is extreme but all dogs can get tangles and knots in their fur.
Dogs coat is matted.
Sometimes the only way to assure that the dog has been brushed thoroughly is to go over the entire body with a metal comb.
Ignoring matted fur in your dog and not maintaining a healthy coat can lead to problems with hygiene in turn posing significant health risks.
Matted and knotted fur can be very painful for your dog and even more painful to try and brush out.
The author of the grooming industry reference guide notes from the grooming table has cleaned up dogs with fur so matted that the only solution was to cut off the entire coat which falls away in one piece like a pelt she says.
Problems with matted dogs.
Brushing the outer coat will make the dog look good but may not get at all the mats.