There are many causes of hair loss in dogs. Some of them are easily treatable, while others such as Schnauzer Comedo Syndrome, which is seen in some miniature schnauzers, will prove to be a lifelong problem for the dog. If you notice that your schnauzer is experiencing hair loss, the first step is to take him to the veterinarian as soon as possible. Once the problem has been pinpointed, you can begin the process of growing back the hair.
Treat the cause of the hair loss. If your dog is losing hair because of a condition such as ringworm or mange, your veterinarian should be able to diagnose the problem and prescribe a treatment. In most cases the remedy will consist of an oral medication, some type of external pesticide treatment, or a medicated shampoo.
Rid your house of any foods or environmental factors that the dog is allergic to. If an allergy is what has caused your schnauzer to lose his hair, continued exposure to the allergen will only make the problem worse. Your veterinarian may also prescribe an antihistamine to relieve the dog’s allergy symptoms.
Feed your schnauzer a healthy, protein-rich diet, avoiding foods that contain a large amount of fats and sugars. Because hair is made of protein -- it requires plenty of new protein in order to grow strong -- and at a steady pace. Adding foods such as meats, eggs, and fish to the dog’s diet may jump-start hair growth, in addition to providing valuable overall nutrition.
Give the dog supplements of vitamins or hormones, if suggested by your veterinarian. In particular, the levels of vitamins A, B, and K in your dog’s body can greatly affect the growth of his coat. A sufficient amount of iron and magnesium in the blood is also vital, to both the growth and quality of your dog’s hair. If the hair loss has been caused by a condition such as diabetes or hypothyroidism, your schnauzer will need to be given hormonal supplements to remedy these issues, likely for the rest of his life.
Avoid excessive brushing or combing of the dog's hair. It is important to keep your schnauzer well-groomed, but overdoing it will only cause the hair to become brittle and break easily. You will also want to minimize the use of hot water or blow dryers on your dog's coat, as these can be very damaging to hair.