Cats purr for a variety of reasons, and it is not always an indication of happiness or contentment. Here are some possible explanations for why a cat might purr deeply:

• Happiness: Purring is often a cats way of expressing pleasure and contentment, such as when they are being petted or cuddled.

• Self-soothing: Cats may also purr when they are stressed or anxious, such as when visiting the vet. Purring can be a way for them to self-soothe and calm down.

• Communication: Kittens start to purr when they are only a few days old as a way to communicate and bond with their mothers. Adult cats may also purr to communicate with other cats or animal companions.

• Requesting food: A high-pitched purr that starts close to mealtime may be your cats way of requesting food.

• In pain: Cats may also purr when they are in pain or injured. Purring frequencies have been shown to stimulate bone regeneration, so it is possible that cats purr as a way to promote healing.

To interpret your cats purring, you can look at the circumstances around the purr. For example, if your cat is curled up on their bed or your lap, grooming or being groomed by a housemate, or relaxing in the sun, their purr is likely a sign of contentment. However, if your cat is displaying changes in facial expressions or purring accompanied by a twitching tail, wide pupils, or panting, they may be in distress.