Preventive care at home:
There are certainly ways to ensure your cat stays in peak condition for as long as possible. These include;
Feeding a good quality, nutritious diet
Dental care
Maintaining proper parasitic control
Keeping a close eye on your cat's general wellbeing and seeking veterinary advice as soon as you notice changes. Not only would these include obvious signs of sickness such as injury etc., but also indicators such as change in eating or litter box habit, unkempt coat, general lethargy, change in behaviour.
Being aware of your cat's weight.