A survey of 1240 normal cats showed that cats become more grumpy as they age. Hidden pain is a possible cause of increased grumpiness.

On average, kittens and older cats are more tolerant of handling. Reduced tolerance in older cats might indicate chronic pain.

On average, older cats continue to take care of their appearance. Altered grooming habits might indicate stress or chronic pain.

Appetite varies between individuals. Altered appetite is a key indicator of poor health in cats. A reduced appetite might indicate chronic pain.

The average cat becomes less playful as they grow older. Reluctance to play might indicate chronic pain.

On average, cats become less social as they grow older. One of the reasons might be discomfort associated with vigorous play.

A survey of 1240 normal cats showed that normal elderly cats have no problem walking. Reduced walking ability might indicate pain.

Like people, elderly cats lose some of their willingness to run. Severely limited running ability might indicate chronic pain.

As expected, elderly cats are less willing to jump onto furniture. Obvious limitation is one of the best indicators of chronic pain.

Reduced high-jumping ability is a consistent feature of chronic pain. Lower back pain is a classic cause of reduced jumping ability.

Reduced hunting ability is a probable (but unproven) consequence of chronic pain. The mouse community has declined to comment.