Circadian Rhythms

Dog activity throughout the day
By Karen B. London PhD, September 2014, Updated July 2016

It’s such rotten luck than just as many of us are coming home from work hoping to chill out, our dogs are ramping up for high activity. When dogs go nuts at that time of day, their happy reunion with us not the only reason. Most dogs naturally exhibit high energy and elevated activity levels in the early evening. That’s why it’s so important to spend some time with our dogs then. It pays to get them outside and exercising, even though that may not always be our first inclination.

Dogs are also ready for some action in the mid-morning, and this is also species-typical. They are inclined to be active at certain times of the day just as birds are inclined to sing at sunrise and coyotes tend to howl during the night. The tendency to behave in certain ways over the course of the day is part of the daily cycle called a circadian rhythm. Many living organisms have circadian rhythms, including animals, plants, fungi and even bacteria.

The light/dark cycle of our rotating planet is responsible for the circadian rhythms that lead to the predictable timing of behaviors throughout the day. Light leads to changes in the hypothalamus, which regulates these daily rhythms. The pattern of light affects sleep cycles, hormone levels, brain wave activity and body temperature, all of which have an impact on behavior.

Dogs certainly have a natural circadian rhythm with activity peaks in the mid morning and early evening. Although dogs may vary in how closely they follow this typical pattern, few adult dogs are completely at odds with this normal schedule.  Puppies, on the other hand, are not born with a circadian rhythm, and it takes months for them to develop the pattern typical of their species. Their active times are not as predictable as those of adult dogs.

Is your dog predictably active at certain times of the day?

photo by Danny Ayers/Flickr

Karen B. London, PhD, is a Certified Applied Animal Behaviorist and Certified Professional Dog Trainer who specializes in working with dogs with serious behavioral problems, including aggression. She has authored five books on canine training and behavior.