Although most canines would prefer avoid it, regular washing is essential for maintaining your dog's hair and skin. Giving your dog regular baths helps to remove dirt and parasites. There's also the bonus of having a dog that's easier to be around.
Most dogs do OK with a monthly bath. Oily-coated dogs, such as Basset Hounds, may require weekly baths. Dogs with short, sleek coats like Beagles and Weimaraners don't need to be washed as often as longer-haired types.
Samoyeds, Malamutes, and other northern breeds with thick double coats benefit from less frequent bathing and more frequent brushing to remove dead hair and disperse the natural oils that keep the skin and coat healthy.
Always brush your dog before bath time. Your dog's skin will get irritated since the water will be trapped in the mats. Take your dog to a groomer if the mats are too difficult to remove with a brush or scissors.