Why Do Pets Sleep So Much, and How Many Hours of Rest Do They Really Need?
Cats sleep two-thirds of their life away. That's sixteen hours or more each day spent in catnaps curled in the sun atop a windowsill perch, wall-mounted shelf, or basket—this means our feline friends sleep more than any other mammal, except for the opossum and some bat varieties. Dogs are no slouches at naptime, either. Adult dogs average 10 to 14 hours of sleep a day with elderly pets and giant breeds sleeping the most. So, what's up with these furry sleepyheads?
Newborn kittens and puppies spend nearly 20 hours a day asleep. They fall directly from playtime into a deep sleep, undisturbed. Adult dogs and cats are different. While humans may sleep in eight-hour (or longer) sessions, adult dogs and cats sleep in short "quiet" and "active" cycles. Because they only acquire deep, restful sleep in short spurts, dogs and cats need more total sleep to accumulate enough of the truly restful sleep they need.
The Sleep Cycle for Dogs
For an adult dog, his sleep cycles from a quiet to active status about every 20 minutes. The sleeping dog spends 75 percent of the time in quiet sleep, and the remainder in REM cycle (rapid eye movement) during which dreams occur. The dog's brain is just as active during dreams as when he is awake. During REM sleep, the body experiences a kind of "sleep paralysis" so that the dog doesn't react to the brain activity other than the occasional dream-state twitch or whimper. In addition, for every 15 minutes the dog sleeps, he spends another five minutes semi-awake but drowsy (sort of like the dog's version of a catnap). A dog may experience about 23 of these sleep-wake cycles over the course of a typical night.
The Sleep Cycle for Cats
Cats also cycle between deep, restful REM sleep and the light napping phase. When dozing, a cat's brain produces long, irregular waves called "slow-wave sleep," which usually lasts fifteen to thirty minutes total. Sometimes, she sleeps sitting up, in which case her muscles stiffen to hold her upright so that she's ready to spring into action at a moment's notice. When the cat moves from light into deep REM sleep, her body relaxes, she stretches out, and rolls to one side. Her brain wave patterns change and become smaller and closer together and looks similar to her waking patterns. Like dogs, cats can dream during REM sleep. This phase usually lasts only about five minutes, and the cat then returns to slow-wave sleep—and, thereafter, alternates between the two until she finally wakes up.
Answering the Question: What Is Abnormal?
Not getting enough sleep may lead to behavioral issues, while sleeping too much can be a sign of health problems. Pets suffering from anemia, thyroid issues, or pain such as arthritis may sleep more. Deaf pets may get confused about sleep time. Very old pets with cognitive issues may go through "sundowning" and become confused or restless at night. They tend to pace a lot, whine or yowl, and may have trouble falling asleep. Dogs who snore may suffer from apnea, which makes it hard for them to get enough sleep. Flat-faced dog breeds are more prone to this problem.
Cats normally prefer to be most active at dusk and may pester you and want to play at night. Giving pestering cats any kind of attention (even yelling or tossing pillows) rewards the behavior so they continue. Increasing playtime before bedtime to tire them out can help you both sleep better. In rare cases, dogs are diagnosed with a REM sleep behavior disorder. These dogs "act out" their dreams with violent leg motions, loud vocalizations, or even biting.
While our pets sleep well and often, it's important to know what's normal for each individual dog and cat. Always consult your veterinarian if you notice changes in your dog or cat's sleep patterns.