Why is my cat losing weight rapidly? Should I be concerned?

Hi there and thank you for using Petco Pet Education Center, formerly Petcoach to address your concern. There is a lot that we cannot tell from an examination on a pet, especially if it is something like sudden weight loss but the pet is otherwise acting normal. I would recommend having Kini's blood tested to evaluate overall systemic functions and see if there is an explanation for the weight loss. Check thyroid level as well. If all is normal on blood but the weight continues to fall, I would recommend x-rays and an abdominal ultrasound. I hope this helps! Please let me know if you have any other questions or concerns and I would be more than happy to help you further.

Weight loss is possible due to increased activity, but 9kg to 4kg is more drastic than I would expect. I would discuss doing bloodwork with your vet. Increased activity and weight loss is common in cats with hyperthyroidism. Weight loss can also be caused by kidney disease and diabetes. All 3 of these conditions can be diagnosed with simple bloodwork (CBC, chemistry, thyroid panel) and urinalysis.

Weight loss coupled with a normal or increased appetite can be a sign of diabetes or hyperthyroidism, to name a couple of possibilities. I recommend getting Felix seen by your vet as soon as possible for an exam and labwork to determine the reason for his weight loss and get him started on treatment.

Sudden weight loss is always a very big warning light that should not be taken lightly, it's usually a sign of an internal disease that needs to be investigated, i strongly recommend taking him to the vet in order to get it checked, he will need to have a blood test done and possibly an xray as well in order to attempt to diagnose the reason for these symptoms.

Thanks for using Petco Pet Education Center, formerly Petcoach! I’m glad to hear Grippet has lost the weight you wanted him to, but at his age we would want to ensure all the weight loss is for healthy reasons and not an underlying medical issue. As cats age, they frequently can get an overactive thyroid, diabetes, or kidney issues (among others) that can lead to unhealthy weight loss. I would recommend he be evaluated by his regular veterinarian and have bloodwork done to ensure all his weight loss is healthy and there isn’t an underlying issue that needs to be addressed. Good luck!

Hello. Weight loss of that amount is, unfortunately, going to require some investigation. If the cat’s feeding routine has basically remained unchanged, he has been dewormed....then we need to be looking for other, more serious problems. A thorough physical exam, bloodwork and possibly x-rays. He will likely need sedation for all of this, so presenting him to the vet in a humane trap that he can be sedated while still in the trap is the safest method for all involved. Reasons for dramatic weight loss could include diabetes, intestinal diseases, kidney or liver issues, cancer, etc. I deal with feral cats all the time and it is relatively simple to sedate them through the trap in order to do any procedures necessary. Good luck

Significant weight loss is always a concern, especially if his appetite is good. Hormonal conditions such as diabetes and thyroid disease or poor absorption and digestion of his food is possible and I would recommend a full physical and blood panel as soon as possible in order to stabilise his condition before he becomes too frail