16 year old cat losing weight

Max, who is 16, was at the vet for his annual check up in February and our vet pointed out that he had lost some weight. Probably about a pound, I'm not sure. After he pointed that out, I've kept my eye on him to see if anything else is happening. The vet said a lot of older cats get hyperthyroidism, but he didn't think Max showed any symptoms of it. He asked if he was throwing up a lot or drinking more. I haven't noticed either one. Now I'm noticing that he seems to have lost more weight. He still eats all the time, he's inside 90% of the time and only once in 2 months have I found cat puke on the floor and I can't even be totally sure it was his. What are some other causes of him losing weight? When cats coming to their end, do they lose weight like this? I used to get so frustrated with this cat, but I've grown to love him so much and I want to do whatever I reasonably can to help him stick around for as long as he can be comfortable.

There are many reasons that could result in weight loss. Monitor ANY change in the cat's habits.
Try to answer these:
Does he eat less?
Does he eat more, but still loses weight?
Does he drink more?
Does he drink less?
Does he still use his litter box as much as normal?
If so:
Is he peeing as much as normal? If not - more or less pee?
Is he pooping as much as normal? If not - more or less poop?
If he doesn't use a litter box indoors, take him out on a leash only. Don't let him wander. Try to monitor how much he's going.
Is he as active?
Does he sleep more?

As you can see, there are MANY things to watch for. A male cat, near the end of life, can have many problems. My old cat had crystals build up and peeing became very painful for him. Does your cat "cry" when he urinate or deficates?

There are a lot of reasons for cats to be eating normally (or even more) and losing weight. Some of these things are very serious, others not so much with proper medication.

You need to take your cat for a blood test and not let this go. Cats can live to be 20+, and this might be something with a reasonably easy fix.

I'm glad you chimed in on this one LR. You are far more knowledgable about cats than I am.

You are far more knowledgable about cats than I am.

I wish I weren't. I wish I had never seen one of the furry miserable things. :D

I would definitely recommend that you take your cat back to the vet and have blood work done. Our previous cat (RIP) went through the same thing (although I believe she was younger at the time), the vet did some blood test and subsequently did surgery to remove her thyroid. Our beloved Alex lived happily until she was almost 21 yo :love:

I lost my cat in February. She was hyperthyroid and did very well for several years on medication. Hyperthyroidism is easily diagnosed with a blood test. Your vet should have done this already. I would go back and ask him to do it. Without medication, it can cause severe damage to the heart and other organs.