When a cat has scabs scattered evenly all over the back, and even on other parts of the body, miliary dermatitis is a likely cause. If this is the case, the scabs are about the size of a millet seed, and the cat pulls its own hair and scratches in an attempt to ease the itching from the scabs. The owner should be able to see and feel the scabs easily.
The most frequent cause of miliary dermatitis is fleas, although other skin parasites and food allergies are also possible causes, and vitamin deficiencies and hormonal problems also have a connection to it. In some cases, it is a combination of some or all of those factors that lead to the scabs.
Looking at the scab pattern is a good place to start when attempting to determine the most significant cause. Scabs that gather around the cat's neck and along the back's midline before going to cover the rest of the body connote an allergic reaction to fleas. If the scabs are accompanied by hair loss near the rump and toward the neck, cat flea allergy dermatitis is a definite possibility. Scabs on the ends of the back (near the head and tail) are more likely to have a connection with food allergies. To find the best treatment, the first step is to pay a visit to the veterinarian.