If your dog smells, the first thing to check is where the smell is coming from. Is it the skin, or somewhere else? Odors can emanate from many body parts, including:
The mouth, which could mean dental problems, digestive problems or underlying internal dieseases, such as kidney problems or diabetes.
The ears, which could mean an ear infection, especially if accompanied by head shaking, pawing at the ears or rubbing them on the ground.
The backside, which could indicate an anal gland problem or flatulence caused by digestive problems. Some long-haired breeds may have soiling due to feces sticking to the long hair in the area around the anus.
Once you have determined that the smell is in fact from the skin, the solution can be determined more easily. Many dogs have a habit of rolling in the most revolting places (feces) that smell awful. Prevent this by bathing your dog. Pick up any feces in the yard as quickly as possible to remove any temption.
Dogs have a self-cleaning mechanism in their coats. They have glands in its skin which produce sebum, an oily substance which helps lubricate, waterproof and protect. Sometimes this mechanism breaks down, most commonly when there is an underlying skin disease such as infection or an allergy. Take a look through your dog's coat to the skin. Are there flakes of skin present (doggy dandruff). Is it very oily, waxy or sticky? Is it red and inflamed? Is the skin raw underneath? If yes, it is likely your dog has a skin disease.
A visit to your veterinarian may be in order to diagnose the problem. A holistic vet will get to the root of the problem and usually does not resort to steroids and other dangerous medications.
Human shampoo can irritate dog skin by being too acid. A good all-purpose shampoo for dogs should be one which is designed for canines, not humans. Be sure to rinse thoroughly, any shampoo residue can become itchy or sticky and cause the coat to look dull when it dries.
A homemade diet or feeding a high quality holistic pet food will make a big difference in the skin, odor and health of your dog.