Dog Anxiety & Aggression and Links to the Gut
Written by Seana K. Davidson, PhD
Published on February 5, 2019
Anxiety and aggression are common problems in dogs. In fact, it’s estimated up to 70% of behavioral problems in dogs can be attributed to some form of anxiety, according to the Journal of Veterinary Behavior. As strange as it sounds, the bacteria that live in your dog’s gut (digestive tract) may affect their mood, and therefore their behavior. Evidence suggests that the gut influences the brain, and these two are constantly communicating with each other.
In this article, we’ll explain what the gut microbiome is and how it communicates with the brain via the gut-brain axis. We’ll also share exciting research which suggests that certain behavioral problems in dogs may be fueled in part by imbalances in the gut microbiome. In the future, we may be able to positively impact our dogs’ moods and behaviors by altering their gut.
Understanding Bacteria in the Gut
Most people associate the digestive system with the job of processing food. The digestive tracts of both people and animals are filled with trillions of tiny organisms (bacteria, fungi, viruses, and others), collectively called the gut microbiome. These organisms help break down food, creating fuel that feeds cells throughout the body. They also support the immune system, and regulate the metabolism to help maintain a healthy weight.
But that’s not all these bacteria do for their hosts. Studies in both animals and humans are finding important connections between gut bacteria and the brain that influence emotions, including psychological disorders like anxiety and depression. Recent evidence is also implicating these tiny organisms in influencing the emotions of dogs, possibly causing anxiety that in some cases may lead to aggressive behaviors.
Bacteria in the Gut Communicate With the Brain
Gut bacteria make chemicals that communicate with the brain through nerves and hormones. This connection between the gut and brain is called the Gut-Brain Axis.
In humans, clinical studies are finding that gut bacteria send important chemical messages to the brain, and these chemical messages can have a big impact on one’s mood. The effects depend on which bacteria are in the gut, because different bacteria make different chemicals. Certain bacteria make chemicals that have a calming effect, while others may promote depression and anxiety.
The Anxious Gut and Dog Well-Being
Most of the research to sort out how gut bacteria are talking to the brain was studied in non-human animals. That's good news for pet parents, because these studies are very relevant to pet health.
For example, feeding mice certain probiotic bacteria (Lactobacillus and Bifidobacteria) resulted in chemicals being sent to the regions of the mouse brain that regulate emotions. These bacteria sent signals that decreased anxiety and depression in these mice.
Could microbiomes in dogs also have effects on their emotional well-being?
The study sampled gut bacteria from 31 dogs confiscated from a home where a dog-fighting ring was taking place. Researchers assessed each dog for aggressive behaviors and divided them into two groups: dogs that displayed clear aggression, and dogs that were not aggressive towards other dogs.
After analyzing their gut microbiome - by carefully sampling their poo - the researchers found that certain groups of bacteria tended to be present in higher levels in the aggressive dogs. Their conclusion was that certain kinds of bacteria in the gut microbiome may be linked with aggression and other anxious behaviors.
The researchers made an important point that anxiety is sometimes linked to aggressive behaviors. Indeed, anxious dogs are more likely to show aggressive behaviors than their non-anxious counterparts.
Is it Possible to Address Behavioral Issues Such as Anxiety by Shifting the Doggy Microbiome?
While consulting with a dog trainer is imperative if you have an anxious or aggressive dog, it is equally important that the dog has good health. Health conditions such as atopic dermatitis and chronic digestive issues can make a pup uncomfortable and anxious, and are associated with imbalances in gut bacteria.
The gut microbiome is an ever-changing ecosystem that is impacted by many factors, including diet, medications (like antibiotics), and the environment.
Evidence is growing that it is possible to change the signals from the gut bacteria to help calm the emotions, decrease inflammation, and increase overall health and well-being.
While there is still much to learn, it is quite clear that the gut microbiome plays an important role in countless physical and psychological processes in our pups. That’s why we say that a healthy pet starts with a healthy gut.
To find out more about your dog’s gut health consider a microbiome test kit from AnimalBiome that tells you precisely what’s living inside your dog’s gut. Based on your dog’s results, the Microbiome Report includes tailored recommendations for supplements to shift the microbiome community to support beneficial bacteria associated with lower levels of anxiety and aggression.
You may also enjoy reading, Have an Anxious Pet? Anxiety & Dog-Cat Gut Health.
If you liked this article, please consider sharing it.