The cat's state of suspended animation and cessation of breathing can last up to 1-3 hours. The state of suspended animation mostly occurs in newborn cats. The mother cat takes too long to give birth to the kittens and lacks oxygen supply. The kittens will not breathe after birth but the heartbeat is still there. At this time, the owner needs to rescue them. If an adult cat appears to be in a state of suspended animation, it may be a sudden illness and it needs to be sent to a doctor for treatment as soon as possible.