Many dog breeds or crossbreeds have long, wavy or curly hair. Dog breeds that do not shed as often as other breeds include the poodle, any poodle-cross, the Bichon Frise and the Portuguese water dog. Instead of falling off of the dog, the dead hair stays trapped in the coat. Dog breeds with exceptionally long fur, such as the Pekingese or the Yorkshire terrier, get tangles often. If dogs with long or low-shedding coats are not groomed regularly, their hair will tangle and trap dirt, feces and bacteria next to the skin, which causes infection and pain.
Give your dog a chew treat or bone to distract him the discomfort of the dematting process. The dog may ignore it if it has never been groomed before. This is common among dogs rescued from hoarders and puppy mills. In this case, the dog may stay still and unresponsive out of fear.
Spray the mat with a conditioner specifically for detangling matted dog hair. Hold the mat out so your fingers are between the dog's skin and the tangle, if possible, to help numb the sensation of hair being pulled. Use a wide-toothed comb or a dog grooming rake to slowly loosen the outside hairs of the tangle.
Use a mat splitter on a tangle only if the dog is quiet and the matt has a good chance of coming out. Skip the mat splitter if the dog is anxious or if you are getting nervous. Mat splitters are very sharp and need a steady hand and a still dog. If the dog is still, insert the mat splitter's blade into a chunk of the mat to pry the mat apart. When a large mat is split into a few small matted strips, take the rake or wide-toothed comb and comb it smooth.
Stop if the dog is getting stressed or violent with pain and the mat just will not comb out. If a dog is covered in mats, the dog may only tolerate a few mats being combed but not all of them. In these cases, call a veterinarian or groomer to have the dog's coat shaved down. The dog will need to be tranquilized before the procedure, especially if this is a rescue dog that has never or rarely been groomed.