Why cats purr.
Experts surmise that purring is a way for kittens and momma cats to communicate with each other. Since kittens are born both blind and deaf, the vibration of a mother cat’s purr helps guide them to suckle. When these babies become toddlers and adult cats, purring takes on other functions, such as asking for attention, socializing with other cats, or expressing contentment. Cats also purr, however, when they’re ill, hurt, stressed, or angry.
If your cat purred and suddenly stopped, you should see a vet, especially if the change is accompanied by lethargy and decreased appetite. Your kitty could have something else going on that needs to be addressed.
Some cats just don’t purr.
All cats exhibit individual personalities, and purring may just not be a cat’s chosen method of communicating. Instead, your non-purring kitty may use facial expressions or body language to solicit a request for food or affection. It’s also possible you’re unable to detect the purring because it’s so soft and subtle.
Fret not. A non-purring cat with no other adverse symptoms isn't necessarily experiencing pain or unhappiness. It’s just that he doesn’t find it necessary to vocalize when he’s content, hungry, or seeking affection.
Can I encourage my cat to purr?
Animal experts say there really isn’t much you can do to coax a non-purring cat to vocalize if they’re not typically a purrer. However, if your cat is on the quiet, modest side but is capable of purring, you can try a variety of things to encourage your cat to purr more.
Whether or not you are able to prod your non-purring cat to purr doesn't really matter. What is important is that you give him plenty of strokes, love taps, and gentle words of encouragement to ensure a purr-fectly healthy, happy kitty.