Cortisol and Your Dog’s Brain


The Link Between Cortisol and Behavior


As we discussed in the ‘Is Your Dog Trying to Talk to You?’ blog post, all dog behavior is communication. And canine behavior is influenced by many factors; genetics and breed, age and phase of development, gender, learning history, environment, pain levels, quality and quantity of sleep, quality and quantity of exercise, emotional state of the dog and those around them, and stress levels.


This blog post focuses on stress levels, and how stressors can change cortisol levels in your dog’s body. Both overwhelming and overstimulating experiences can result in significantly increased cortisol levels, which can then cause all kinds of stress-related behavior such as hyperactivity, reactivity, compulsive behaviors, and yes, even increased “aggression”.


Cortisol, just like in humans, is the primary stress hormone…it also helps regulate body weight, blood sugar, and other aspects of general health and well-being. But cortisol is probably most well-known for activating the sympathetic nervous system and preparing the body for ‘fight or flight’. Just like in humans, prolonged stress and excessive cortisol not only results in less than ideal behavior, but it puts health at risk. Stress hormones can accumulate and take some time to dissipate….it can take up to 72 hours for cortisol levels to return to normal, which means it can trickle down into behavior for days. And for dogs who regularly experience overwhelming or over arousing events, cortisol levels stay elevated long term. Just like with people, this means a more touchy and edgy dog in general who is quicker to overreact to things.


What causes a surge of cortisol in your dog? It depends on the dog! 


For some dogs, car rides are extremely stressful. Does your dog bark, whine, or chase cars through the window? That might mean that car rides are too stimulating for your pet. One way to reduce stress in the car is to put your dog in their crate and cover the crate with a blanket. Provide your dog a chew toy or food puzzle to relieve stress. 


For some dogs, playing fetch is too over arousing. Does your dog show obsessive or addictive behavior about tennis balls? That might mean that 15 minutes of fetch is more overstimulating than exhausting for your dog, and all that cortisol produced can tip your dog over into undesirable behavior. When you only have 10 or 15 minutes to exercise your dog before, during, or after work, you may think your dog wants to play fetch, but if your dog shows signs of overstimulation with the tennis ball (can’t think or respond to cues, dilated pupils, happy to run through a brick wall to get the ball)…that’s not healthy or beneficial. We’d suggest you go for a bike ride or jog instead. 


For some dogs, having other animals or children around is too stimulating. Does your dog excessively bark, pant, or yawn in the presence of other animals or kids? That might mean that the park, outdoor seating at a restaurant, or a friend’s backyard barbecue is more stressful than fun for your dog. Perhaps you can walk your dog someplace quiet before the event and leave him home to enjoy a big fat bone to gnaw on instead.


How do you reduce stress in your life? Many humans use walks in nature, meditation, and yoga to reduce stress and lower cortisol levels. Your dog needs to reduce stress too, and low stress levels are key to good quality of life. Dogs find sniffing, chewing, shredding, and licking all soothing and stress reducing, and these activities lower canine cortisol levels. Let your dog be a dog and fulfill their biological needs with enrichment (visit our ‘Resources’ page for more enrichment ideas) and you’ll notice a more contented dog and better behavior!