Gut Flora and Dog Behavior

The microbiome, or microbiota, is better known as gut flora. It refers to the microorganisms that regularly live in the digestive tract. A good portion of them aren't just harmless — quite the opposite, they're beneficial.

Because of this, they play a role in a dog's health. On top of that, a link has been shown between gut microbiota and the nervous system and behavior. That's why it could play an important role in treating and understanding various disorders.

The Importance of Canine Gut Microbiota

Studies continue to be conducted today on the link between gut flora and various neurological conditions. Just like in human medicine, this is also a developing research area for dogs.

It's known that bacteria living in the intestinal tract can produce various metabolites that affect the brain. In other words, gut microbiota can influence a dog's behavior, as well as its neurological development. This aspect is being researched in veterinary medicine.

Especially given its possible link to aging processes. Dogs are known to suffer from so-called cognitive dysfunction syndrome, a condition comparable to Alzheimer's in humans. Given these similarities, research in this area could benefit both species and improve prevention and treatment.

Microbiome and Aging in Dogs

A study conducted at Eötvös Loránd University in Budapest linked gut flora composition with a dog's age and memory ability. It involved 29 individuals who were given a memory test.

Right after, fecal samples were taken from all of them to analyze a bacterial gene, specifically the one known as 16S rRNA. In the samples' composition, populations of Bacteroidetes, Firmicutes, and Fusobacteria stood out the most. Older dogs had a lower percentage of Fusobacteria.

Dogs that did better on the test, showing better memory, had samples with fewer Actinobacteria. Surprisingly, people diagnosed with Alzheimer's are characterized by an abundance of Actinobacteria in their digestive tract.

Cognitive Dysfunction Syndrome in Dogs

Although the Hungarian university's study opens up interesting possibilities, we need to keep in mind it was conducted on a small sample of dogs. Its results should be interpreted with that in mind.

Even so, it's another piece of evidence for the link between gut flora and brain behavior, also factoring in age. It's an open door for further research into canine aging and neurological development. Remember, cognitive dysfunction syndrome shows up in elderly dogs.

It causes symptoms like disorientation, eliminating feces and urine at home, changes in sleep schedules, and so on. It's an irreversible process that today can be managed, though not cured, with certain medications, nutraceuticals, diet, or management guidelines.

Canine Aggression and Gut Microbiota

The results of the interaction between gut flora and the brain are so surprising that a link has even been found with aggression. This is a serious behavioral issue that can pose a high risk to people and other animals.

Unfortunately, it's not unusual for this disorder to end badly for the dog, which gets abandoned or euthanized. Although this field still needs more research, today a link has been found between a dog's behavior and the microorganisms living in its digestive tract. So far, there's one completed study on this.

The Study Linking Canine Aggression and Gut Microbiota

The Oregon State University study was based on 31 Pit Bulls that had been used for fighting. All were rescued, examined, and classified as aggressive or not. Fecal samples were also collected from each.

All showed populations of Firmicutes, Fusobacteria, Bacteroidetes, and Proteobacteria. It was found that Proteobacteria and Fusobacteria were significantly more abundant in dogs classified as non-aggressive. Meanwhile, Firmicutes populations stood out in those labeled aggressive.

Although this is a very small sample of dogs to draw conclusions applicable to the whole species, it opens up a very interesting research path. For example, confirming the proposed hypothesis would mean it could be possible to diagnose aggression by analyzing a dog's fecal sample.

Bibliography Kirchoff, Udell, and Sharpton. 2019. The gut microbiome correlates with conspecific aggression in a small population of rescued dogs (Canis familiaris). PeerJ 7:e6103 https://doi.org/10.7717/peerj.6103

Kubinyi, Bel, Sándor, Szabó, and Felföldi. 2020. Gut Microbiome Composition is Associated with Age and Memory Performance in Pet Dogs. Animals 10, 1488.