Why is my 10-year-old cat losing weight, not eating, and drinking toilet water?

I'm sorry the hear diamond is not feeling herself. When cats lose weight rapidly we worry about several potential diseases including kidney disease, diabetes (they tend to be drinking a lot of water with these two), increased thyroid level (hyperthyroidism), and disease in the intestine (inflammation or even cancer). I would have diamond evaluated by a veterinarian. A physical exam and Simple lab work will help start sorting out what could be going on. I hope you get answers soon and diamond is feeling better.

Poor Little Man! His lethargy, weight loss and excessive drinking make me concerned about several possible conditions, including kidney disease, hyperthyroidism, and diabetes, among others. At this point, he needs to be seen by his vet for an exam and lab testing (CBC, chemistry, T4 - thyroid) to evaluate his organ function. There isn't much that you can do at home without determining the underlying cause of Little Man's clinical signs.

My concern with Menie is that he can have one of a few different things going on. As cats age they can become diabetic, have chronic kidney disease or even become hyperthyroid. With all these diseases you will see an increase in drinking and weight loss. I would recommend taking Menie to the veterinarian and having blood work and a urinalysis performed to see exactly what is going on with him. The urine will also show if there is a urinary tract infection, which they can have if they have diabetics, kidney disease or even if they don't have another disease going on. I hope Menie feels better soon and thank you for using Petco Pet Education Center, formerly Petcoach.

This is very concerning and may not related to progressing kidney, thyroid disease or diabetes. An urgent vet check and urine and blood tests is recommended. Do not delay investigation as early treatment is required

In an older cat, my first thought would be dental disease. This would be painful for Krinkle, cause him to eat less, and subsequent weight loss. It could also be that he has diabetes, kidney failure, or hyperthyroidism. Having him seen by a vet this week is a good idea. I hope this helps!

I would have Zarry checked out by a vet as soon as possible. There are two conditions that come to mind that can cause a cat to lose weight despite having a good appetite: hyperthyroidism and diabetes. A vet will examine Zarry and discuss his medical history, and will probably recommend bloodwork to look for a diagnosis.

It is fairly rare, but ask your veterinarian if your kitty may be suffering from Cushing's disease or liver disease. Also sometimes cats can still be hyperthyroid, even though the thyroid parameters are within normal limits (this is called euthyroid sick). He could also have a tumor. In any case, this needs to be investigated further.