Skin Problems
The skin is the largest organ of the dog's body and a frequent source of problems as well. The job of the skin is to protect the inner organs and tissues from invasions by foreign substances, changing temperatures, and dehydration. The skin also works to synthesize essential vitamins for information about the external world through sensation.
Normal canine skin is smooth and flexible. Colors range from pale pink to brown to bluish black. Spotted skin is normal in any dog, even those coats that are uniform in color. Lumps, bumps, scabs, patches of hair loss, or parasites shouldn't be visible anywhere on a healthy dog's body.
Dogs have seasonal shedding cycles, which don't always behave according to a strict schedule. There are so many different kinds of canine hair that it's difficult to draw a typical picture. Obviously the hair of a Miniature Schnauzer shouldn't grow in like that of a Golden Retriver. Perhaps it's best to concentrate on what hair shouldn't be. It shouldn't break or pull out easily, or seem excessivly dry or oily. In a smooth-coated dog, the coat should not appear dull or weak. Any sudden or significant change in the hair's appearance should be brought to the attention of your veterinarian.
You should also know that there may be many health issues that can cause hair loss. If the dog has a thyroid condition, for example, the dogs coat will sometimes become dull, and will also fall out in patches usually along the sides of the dog. If you notice any changes in the dogs coat, you should consult with your veterinarian to make sure all is well with your pet.