This is a test of commonsense. Complete the next sentence:

How to keep your mature cat healthy
Be sure your cat's fur is healthy and stays that way.
The quality of your cat's coat will depend on her diet. As your cat gets older the quality of her digestive system becomes less efficient and the nutrients are not absorbed so easily.
When hair coat becomes ragged and thin it's a sign that your cat is unwell and needs to see the vet. She'll be tested for hyperthyroidism which is the most common hormone abnormality in cats, and sometimes only responds to a prescription diet.