What Are the Causes of Hair Thinning in Dogs?

When a dog's hair sheds, it may upset pet owners who want their couches and clothes to remain hair-free. Sometimes the problem is cured with a good shampoo or trim at the groomer's. However, hair thinning in dogs could be the sign of a serious medical problem that requires medical attention.

  1. Fleas

    • This is the most common problem and the one easiest to cure. Many flea medicines, such as the new medicines placed on the back of the dog's neck, must be done monthly. A good flea shampoo is a quick cure for the problem. However, the American Veterinary Medical Association says the best way to keep fleas away from animals is to keep them out of the home. Once they are inside, they can only be removed by an exterminator.

    Allergies

    • Just like humans, dogs can have allergic reactions. According to WebMD, canine allergies can be triggered by the same elements that trigger human allergies: dust, pollen, and other irritants that can be inhaled. Dogs can have allergic reactions to foods and substances that get on their skin. While most humans first experience respiratory problems when exposed to an allergen, dogs experience skin problems. This leads to them scratching and pulling at the skin which can lead to thinning hair and bald spots.

    Mange

    • Many believe that fleas or allergies are somehow related to mange, but mange occurs when parasitic mites dig into the dog's coat or skin. There are two types of mange. Demodicosis is not contagious and many times it clears up on its own. Sarcoptic mange is very contagious and more serious. It is similar to scabies in humans. Often the hair thins first on the elbows and ears of the dog. Dogs with sarcoptic mange must be isolated from other dogs. Rinses and topical creams help kill the parasitic mites causing the disease.

    Endocrine Issues

    • Problems with the endocrine system, especially the thyroid or adrenal glands, can cause hair thinning in dogs. Cushing's Disease is one of the most common problems. Often the problem is caused by prednisone or other corticosteroids that have been prescribed by the veterinarian. In other cases, the disease is caused by a tumor on the dog's adrenal or pituitary gland. Adrenal tumors can be removed by a veterinary surgeon, but pituitary tumors can not be cured. The average lifespan of a dog with a pituitary tumor is about two years after it is diagnosed.