Sudden Weight Loss Causes More Condition_symptoms What Causes Sudden Weight Loss In Cats?

What causes sudden weight loss in cats? - sudden weight loss causes more condition_symptoms

My mother cat is generally pleasant and muscular and stocky, but suddenly lost much weight. He stopped eating, but no symptoms of disease and loss of appetite and weight loss.
My mother is very happy to have her cat and concerned, but can not afford a vet now, maybe in a month. Any help much appreciated