An Extended Lifespan

The inevitability of such aging exists all cats, although some breeds, such as the Siamese and Oriental Shorthair, have aging clocks set to run longer than others.

The more important effect we have on the lifespan of cats is through our intervention in caring for them: pet cats are more likely to live out their full potential life-span than are feral individuals.

Generally speaking, pet cats  live more than twice as long as cats in the wild. Evolution did not provide for the security of  living with us, with guaranteed food and shelter into old age.

The consequence of this "unnatural" lifespan is the appearance of  unexpected, age-related design problems not seen in the wild.

For example, a menopause never evolved in female feline design, simply because cats in the wild naturally die relatively young. In the security of our homes, elderly unneutered female cats will continue to have cyclical heat periods.

Because feline evolution did not "design" for this long continuation of seasons, problems arise: while young female cats have a low incidence of womb infection, the incidence is quite high in unneutered elderly cats.

The cat is the most fortunate of all the species that humans have domesticated, in that we have interfered least in its natural, evolutionary design. 

Even so, in the cats relatively new ecological niche of living with us, we have put unforeseen pressures on its superb anatomy and senses. Although we are often unaware of it, the lives of many of our pet cats now involve chronic low-level stress.

It is this chronic stress, more than any other factor, that compromises their natural design. Elderly cats are less able to turn off their stress response than young cats: even when they are relaxed, elderly cats will secrete more stress-related hormone than their younger counterparts.

Simultaneously as natural aging progresses, the cat's brain and nervous system also produce fewer of the chemicals called neuroendocrines; specifically, production of the brain chemical dopamine drops.

Dopamine is the brain's "master" chemical: if dopamine production can be maintained, it may be that all aspects of the cat's design can continue to function for longer.