Dog owners know for sure, a dog knows exactly when it’s dinner time or when it’s time to get up or go for a walk, you name it. Dogs clearly indicate to us that it is ‘the highest time’, but does a dog really know what time it is and does a dog really have a sense of the passing of time? When dog owners leave their dogs alone at home, that unanimous opinion suddenly turns into a discussion. “A dog really does not know how long you are away”, it is said regularly. Does your dog know the difference between 5 minutes and 2 hours? A number of theories have been tested and investigated.
Biological clock, life rhythm
Like dogs and many other animals, dogs also have a circadian rhythm. This is an internal biological rhythm whose cycle lasts about 1 day. These are functions that are performed within the body and that repeat according to a certain pattern, controlled by the so-called biological clock. This functions independently of environmental factors such as light and temperature. Consider, for example, body temperature. This changes during the day and is lowest during deep sleep. Consider, for example, the secretion of certain hormones, the volume of the bladder, or the need for eating or drinking. The feeling of hunger is therefore part of this and also affects the behavior. A dog can therefore observe the course of time through the feeling in his stomach or bladder. When you know this, it is not surprising that dogs tell us when it is dinner time or when they have to go outside.
Length of time
In 2011 a study was conducted at a University in Sweden on the effect of the length of time that dogs were left alone by their owners on the behavior of the dog. They examined the behavior of multiple dogs without behavioral problems such as ‘separation anxiety’ or ‘not being able to be alone’. These dogs were left alone at home by their owners for half an hour, 2 hours and 4 hours. The dogs were filmed and filming was started 10 minutes before the owner left, and walked for another 10 minutes after the owner returned home. Especially between the passing of half an hour and 2 hours, there was a remarkably large difference in the behavior of the dog. When owners returned after 2 hours, the dogs reacted considerably more enthusiastically, more intense and longer contact was sought. Also, more stress signals (especially tongue and shake) were observed when the dogs were left alone for more than half an hour. Although this does not concretely prove that dogs are aware of the passage of time, it does show that the length of time that dogs are left alone has an effect on the dog.
Environmental factors, ‘What time does it smell?’
As time passes, the environment changes. We can think of, for example, light, humidity or temperature, but when we talk about dogs, we must certainly remember that also odors change during the day. Professor Alexandra Horowitz, a renowned behavioral expert, researcher and author of the book ‘Inside of a Dog’, emphasizes that dogs have an exceptionally high sense of smell and that they observe the world first through their noses. Dogs smell perhaps 100,000 times better than humans. She thinks that it is quite possible that dogs observe the passage of time through changes in the concentration of certain odors. The past is indicated by weaker, vagere smells and stronger, fresh smells let dogs know that little time has passed.