The best way to know what skin disease your dog has is to take the dog to a veterinarian, the American Society for the Prevention of Cruelty to Animals reports. Skin conditions caused by parasites such as fleas, may be easier to identify because you can see the bugs.
Doctors can diagnose skin diseases using a variety of tests, depending on what the veterinarian suspects. The veterinarian may take a scraping of the dog's skin and hair, then examine it under a microscope. Skin biopsies may be necessary for some conditions, according to the ASPCA. Allergy and blood tests may also be necessary to check for causes.
Dogs can get more than 160 different skin diseases, notes PetMD. These can include bacterial infections, allergic reactions, insect bites and fungal infections. Some conditions, such as flaky and oily skin known as seborrhea, are the result of dietary deficiencies. These conditions are usually curable, although some dogs are prone to chronic skin problems.
Other skin conditions are not curable, reports PetMD. These are often the result of underlying diseases, including autoimmune disorders, hormonal imbalances and genetic conditions. Treating the underlying cause of the disease can help, but some of those conditions are not curable. There may be medications available to manage the symptoms.