We now have a new concern about our soon-to-be 15 year old cat Nobuku. In 1-1/2 months time he's lost half a pound, which doesn't seem like much but is for cats. We do not have him on a diet and his daily food regimen hasn't changed. All of his blood work came back stellar so the next thing is a possible biopsy if the weight loss continues.
Meantime, he seems just fine. He is still active and alert though, he doesn't want to go outside like he used to. The vet says this may be due to partial hearing loss, fear of being unable to run/move fast enough if necessary or his desire to sleep even more. Either way, I no longer carry him outside to make him exercise even though I'm seated outside with him to offer support, if needed.
It's rather strange to see my cat growing old and realize that we too are changing in parallel. Some humans may not want to accept our similarities!