I think that this is what is described as an existential question. The simple answer is that we (humans) don’t know if cats know that they are going to die one day. However, my gut feeling is that cats don’t know that they are going to die because they are not self-aware.
Another similar question is ‘do pets know when they are going to die?’ which I find to be a silly question because nobody knows when they are going to die unless they are close to death.
I know that there are stories of pets seemingly showing that they understand that a human or another pet is dying but as far as I am aware there is no evidence that a cat understands that he or she has a limited time as a living creature.
This does not mean that cats don’t understand that they will die one day. It means that we don’t know because we can’t ask a cat how he feels about dying and a cat cannot tells us through body language or cat vocalisations which confirms to us that a cat understands that he will die one day.
That’s about all that can be said on this subject. I know that there are many cat guardians who will say that their cat told them that it was time to die. This is a very subtle and interesting subject. And it is slightly different. I mean there is a difference between understanding that life is limit and will end and understanding that one is near death.
There is something to be said about the moment near death when a cat can communicate to their owner that it is time to go. But I think this comes down to a sensitive cat guardian understanding their cat so well that they are able to read body language accurately.
There is cat body language associated with a cat dying. There is that look in the eye, possibly an definitive inability to eat, a distinct tiredness of life, all after a long-standing illness which the cat’s guardian knows is terminal. These are a conglomeration of signs and pieces of information which includes their cat’s demeanour and behaviour allowing a person to feel that their cat is telling them it is time to die.
This is my interpretation of this difficult subject. I tend to take a very realistic and if possible a scientific approach to it. I know that others, who are excellent and long-term cat caregivers, will have had experiences which they believe inform them that their cat knew that they were going to die. I get that and they may be correct.
The bottom line is that people don’t know for sure if cats know that they are going to die one day. And there is another existential topic which we don’t know much about; are cats self-aware? If cats don’t know that they exist they can’t know that they are going to die or have a limited lifespan. Perhaps we need to better understand this about cats before we can answer the question in the title. My impression is that cats are not self-aware. This leads to the conclusion that cats don’t know that they are going to die.