Dogs

　　Because dogs cannot speak, we have no way of knowing what appears in their dreams. The editor will take you to understand dogs' sleep: what does it look like when a dog is deeply asleep? What kind of sleep is considered high-quality for dogs?
　　1. What is Deep Sleep in the Dog World
　　Dogs and humans, as advanced mammals, sleep not only to rest their bodies but also to allow the brain to rest and help organize memories. The deep sleep that enables brain rest is called "non-REM sleep," as opposed to "REM sleep," which allows the body to rest.
　　"REM sleep" refers to the state when the body is asleep but the eyes are still moving. When dogs feel safe from their guardians and environment, this safety signal is sent to their brain, helping them gradually enter deep sleep, i.e., "non-REM sleep," allowing the brain to rest fully.
　　2. Dog Sleep Frequency
　　Reminder: Dogs have a sleep frequency of 45 minutes, which is exactly half of a human's.
　　The body and brain cycle repeatedly between REM and non-REM sleep, with the awake and light sleep states acting as transitions. Generally, light sleep accounts for about 80% of the sleep.
　　Dog sleep process:
　　1. Drowsily entering sleep;
　　2. Beginning light sleep state;
　　3. Entering deep sleep;
　　4. Deep sleep, classified into stages 1-4, which restore fatigue, eliminate stress responses, enhance immunity, and repair damaged tissue;
　　5. Then the body prepares to wake.
　　3. Sleep in Elderly Dogs
　　Now we know "deep sleep" is the best way to eliminate fatigue, but for elderly dogs, as physical functions decline, natural sleep time increases but is mostly fragmented sleep, meaning high-quality sleep cannot be ensured.
　　Without deep sleep, damaged nerve tissues cannot be properly repaired, and normal physiological activities like metabolism cannot be well regulated. The secretion of hormones that activate body functions diminishes, accompanied by irritability and stress responses, which are detrimental to health.
　　Reminder: Elderly dogs often experience metabolic dysfunction and low body temperature, so it is important to monitor the surrounding temperature.
　　4. Comfortable Sleep Quality for Dogs
　　Frequently giving dogs commands to keep their emotions active—such as simple commands like drinking water or sitting during meal times—can stimulate their brain and improve sleep quality.
　　However, this method may not work on some elderly dogs, so moderate exercise can provide more external stimuli to their brain, ultimately helping them achieve deep sleep.