A cat can lose weight with a reduced, normal or increased appetite. Gastrointestinal disease, kidney disease, hyperthyroidism, diabetes, dental problems and tumours are some of many possible causes. It is therefore valuable to know not only that the weight has dropped, but also how appetite, thirst, stool and activity levels have changed.
Regular weighing can pick up a change earlier than the eye can, especially in long-haired cats. The vet carries out a physical examination and often uses blood and urine tests as a first step. The findings then guide whether, for example, blood pressure measurement, a thyroid test or imaging is needed.
Book an appointment if your cat is losing weight without you deliberately trying to slim it down. Seek help sooner if the weight loss comes with vomiting, diarrhoea, increased thirst, marked hunger, loss of appetite or a clearly poorer general condition.