It is not normal for a cat to stop eating or not eat at all. This means the cat is experience pain, discomfort, or nausea. Anorexia is a very vague sign that is seen with many illnesses. Cats will also develop a secondary complication from not eating called hepatic lipidosis (fatty liver disease) when they stop eating. This cat needs to be examined by a veterinarian to determine the cause of the anorexia and start treatment.