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Understanding a Dog's Stress Response

Adrienne is a certified dog trainer and former veterinarian assistant who partners with some of the best veterinarians worldwide.

Dogs only stress about presently occurring events, not future ones.

Dogs only stress about presently occurring events, not future ones.

Stress Response in Dogs

Interested in learning more about a dog's response to stress? I was given a great book by Robert M. Salposky as a gift for my birthday, which was on my wishlist for quite some time. It is titled Why Zebras Don't Get Ulcers. While this book mostly talked about stress in humans, it mentioned a bit about stress in animals. I often pondered about the effects of stress on dogs.

This article is, therefore, inspired by the book and its valuable information. What types of stress do dogs suffer from? Salposky claims that the most upsetting stress in animals comes from acute physical stressors. These are sudden outbursts of stress responses seen in zebras that spot a lion and run for their lives or lions that are starving and must gather as much energy as possible so they can catch something to eat in order to survive.

And then there are chronic physical stressors. These are sustained disasters that cause repeated stress because they are constantly recurring or persisting for a long time. In dogs, there is the stress of being repeatedly left alone day after day, which causes them to suffer from separation anxiety. They also experience stress in an environment such as a shelter.

Salposky adds a third type of stress, which he calls "psychological stressors," which we see in humankind. It's the uncanny ability we humans have in getting stressed just by thinking about events. We can re-create the same physiological stress responses as seen in zebras fighting for their lives just by sitting around and thinking about worrisome future events such as getting ready for a date or thinking about how we are going to pay for a mortgage. Some people even worry far in advance about things such as fear of aging or death. Interestingly, as humans, we are the only animal species capable of suffering from this kind of stress!

Dogs could care less about future dates, financial situations, or other problematic things we worry about in the future. While brontophobic dogs (dogs fearful of thunderstorms) can create a stress response just at the first changes in barometric pressure, or in the case of dogs suffering from separation anxiety, when they notice their owners getting ready to head outside, they lack the ability to get stressed about things too far in advance, as this is not a mammalian trait.

What Happens When Dogs Are Stressed?

The body of dogs and other animals, including humans, is programmed to keep things in balance. In order to thrive, we need to have a certain level of oxygen in our bodies, a certain level of acidity, an ideal body temperature, and so forth. When everything is balanced and in normal working order, it's called "homeostasis." According to Salposky, a stressor is anything that sends the body out of its homeostatic balance. Stress is the body's effort of restoring things back to normal.

What happens when dogs are stressed? You'll see the effects of the fight or flight response along with many other changes caused by the sympathetic nervous system which releases adrenaline.

Sexual drive is tossed out of the window.

When dogs are stressed, the secretion of sex hormones decreases since the need for reproducing isn't important when life is at stake. You see this often when female dogs become reluctant to mate when they are stressed from being taken to a male dog's home. This is why males are taken often to the female's home, but if they are stressed too, male dogs may have problems with erections and may produce less testosterone.

Pain in stressed dogs may be absent.

This stress-induced analgesia caused by the release of morphine-like substances (endorphins and enkephalins) is seen when an animal is hurt but still needs to run for its life. This explains why shock collar corrections (or any other corrections) may be ineffective or may require higher amps when dogs are reacting out of stress and fear (in any case, I don't recommend them in any scenario).

Senses get sharper and pupils dilate.

If you have a dog fearful of gunshots, you may see him startle even when he hears a door slam. This is because his body is hyper-vigilant and prepared to react. Memory and cognition also get better. Your dog may decide to not go near the area of the electric fence where he was shocked in the past or he may remember how unpleasant the slippery floor of a bathtub was, so next time he'll decide he doesn't want to take a bath.

Cognition gets better when it comes to recognizing a threat and reacting. If you are trying to solve a math problem when you are terrified of a snake slithering nearby, you won't be able to solve it, as your brain has more important tasks to think about. Same with dogs, try to tell your dog to sit and stay near a scary object. He'll likely be unable to concentrate and will try to run for his life!

The body is also activated so that it can sprint into action.

The heart beats faster, the breathing rate increases, circulating levels of blood glucose increase, the digestive system shuts down, and blood is diverted from the stomach to the muscles so the dog can sprint in action (this explains why your dog won't eat when he is over threshold).

Stomach contractions stop and enzymes and digestive acids stop being produced.

At the same time though, stress can cause diarrhea. Dogs who are boarded are often subjected to "stress-induced diarrhea." Why does this happen? Stress triggers the digestion to stop at the level of the stomach and small intestine, but at the same, the large intestine is stimulated and its motility increases. This causes less water absorption and therefore diarrhea.

There is an evolutionary reason why stress-induced diarrhea takes place. According to Salposky, all that food sitting in the bowels is dead weight that may have an impact on the ability to sprint into action.

Prolonged Stress in Dogs Can Be Unhealthy

As seen, the stress response in dogs can be quite pronounced and can have an effect on their bodies and mind. If you want to learn how does exhibit stress, you may find reading my article "Signs of Stress in Dogs" interesting. Stress triggers may vary from one dog and another. Some dogs may get stressed when being left alone, others when hearing noises others more for a variety of reasons. Stress can have a cumulative effect on dogs when it presents over and over. This is referred to as "trigger stacking."

As in humans, the effects of prolonged stress in dogs may lead to immune-system problems and illness. For this reason, it's important to take action and teach your dog how to better cope with stress. Nowadays, there are many calming aids and force-free dog training behavior professionals ready to help you out.

This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.

© 2014 Adrienne Farricelli


Adrienne Farricelli (author) on October 01, 2015:

Yes, I guess you are mentioning the anticipatory psychological stress we feel days or hours prior certain events. I am a great sufferer of that type of stress, felt it many times before an exam, a worrisome doctor's appointment or before a flight (I hate flying!).

Jacqui from New Zealand on August 03, 2014:

Interesting hub! Thanks. Interesting that humans are the only animals to have that one stress response!

Adrienne Farricelli (author) on July 31, 2014:

Sangre, and and many of these flight/fight responses occur in humans too!

James N. Whitaker from Dallas, Texas on July 30, 2014:

I enjoy learning several things about dogs. Thank you so much for sharing great hubs.

Sp Greaney from Ireland on July 26, 2014:

Not being a dog owner, I wouldn't have known this could occur. Good hub.

Devika Primić from Dubrovnik, Croatia on July 25, 2014:

Great advice from you about dogs.

Lisa VanVorst from New Jersey on July 24, 2014:

A very informative hub that all dog owners should read.

Eiddwen from Wales on July 24, 2014:

Another great hub for all dog owners/lovers. Voted up/shared.