Sign #1: A Change in Appetite or Thirst
If a cat refuses to eat or drink, this often means the cat is in pain or is otherwise feeling poorly.
Contrary to popular belief, most cats are not finicky eaters.
Watch for changes, such as an increase or decrease, in a cat’s food intake. Eating too much or too little can potentially signify disease. For example, eating less than usual can signify an internal illness or possibly even a dental problem. On the other hand, an increased appetite might suggest testing for diabetes or hyperthyroidism. We’ve recently written a post to highlight 9 common household foods which are toxic to your cat and can cause symptoms of illness. Find it here: Foods Your Cat Should Never Eat
If a cat has increased thirst, especially when accompanied by increased urination, this can point to issues like diabetes or kidney disease.