There are several reasons why a dog's hair can become matted such as a lack of grooming, playing in water, and occasionally as just part of life. Some breeds are more likely than others to become matted. Common areas that tend to get the most mats are under your dog's ears and at the joints of their legs. If you let the mats get too bad, they can reach all the way down to skin level. If the mats have become too severe to brush them out, you may have to take the next step and shave your pup.
Your dog probably doesn't even realize their coat is full of mats, unless they have become so big that they form balls of hair. These can make sleeping very uncomfortable for your dog and can in time start to pull on his skin, causing pain and irritation. At this point, you need to do your dog a favor and shave them down to skin level. Then you can start over with better grooming habits.
Having seen how much work it is to shave your dog because of matted hair, it is easy to see why regular grooming is so important. Be sure you take your time and let the clippers do the work. Your pup will appreciate your care and patience and will come out feeling healthier while he waits for his new coat to grow. Don't forget the sunblock in the meantime!