The microbiome is a complex system composed of many tiny living things. Microbiomes exist all around us. This group of living things are called microbes and they include bacteria, archaea (old bacteria), and fungi. The microbiome not only differs between you and your dog but also between other dogs as well! This system can be influenced by a multitude of factors such as genetics, diet and outside environmental exposure. While the microbiome can be specific between different parts of the body, they also travel throughout many systems! Practically every internal system in the body has a unique microbiome which impacts functioning and health. Important microbiomes we’ll focus on here in relation to canine health are the oral, gut, and skin microbiomes.
The Oral Microbiome
This microbiome’s makeup is dependent on a dog’s breed, age and external environmental conditions (2). An indicator of an unhealthy oral microbiome is the build-up of plaque within your dog’s teeth. Although plaque is a natural process that is known to occur as your dog ages, it can be influenced to prevent excessive build-up and even periodontitis. At the core of the issue, Periodontitis can be caused by changes in the microbial community that may allow harmful microbes to take over your dog’s mouth. One example of this is a group of bacteria called Firmicutes; which if too abundant may indicate the development of Periodontitis. The observable result of the cause is commonly seen as plaque in your dog’s mouth (3). Therefore, regularly brushing your dog’s teeth allows the agitation of microbes and prevents the growth of harmful bacteria within their mouth (4). In dogs, the scientific evidence is still limited to associations of oral microbiota and local diseases. It is encouraged to speak with your local vet if you as a dog owner are concerned about your dog’s risk for periodontitis and a healthy oral microbiome.
The Gut Microbiome
The gut, or gastrointestinal, microbiome is one of the most important microbiomes within your dog! Recent research has determined that this microbiome is able to influence neighboring microbiomes as well! The composition of this microbial community has been studied to vary throughout the gastrointestinal tract. Your dog even begins the colonization of the gut microbiota while inside the uterus and rapidly expands after they are born! Within their microbiome, Helicobacter, a genus of bacteria, is considered a commensal bacterium that predominates not only in the stomach but also the large intestine of healthy individuals (5) Therefore, influencing your dog’s diet is the best way to encourage a healthy gut microbiome within your dog. With this being said, the most common way of knowing whether your dog has a happy gut is looking within their feces. If you need help developing your dog’s healthy diet, we encourage you to look within the nutrition section as well as work with your veterinarian to develop a balanced diet!
The Skin Microbiome
The skin is the largest organ and acts as an important barrier for protection against trauma and maintaining homeostasis (7). Even actions such as itching, rolling on the floor, and cleaning themselves can influence the variation of the skin microbiome due to the action only affecting certain areas! This environment is diversified between areas where there is fur and where there is a mucosal surface like a nose! Factors that influence this area can be dependent on genes that determine the dog’s physical traits and genotype as well as age. Additionally, living with your dog can affect the number of different kinds of microbiota within both you and your dog (8). Canine atopic dermatitis has been studied to be influenced by the skin microbiome. Dogs with this condition were noted to have a lower bacterial diversity between areas with fur and skin when compared to healthy individuals (9).
While this section of research is a rapidly developing field, this article has only scratched the surface of the microbiome as well as the other various communities found within the canine body. We hope that with this information, you as a dog owner are able to integrate this knowledge when learning about your dog’s health.
Sturgeon A, Stull JW, Costa MC, Weese JS. Metagenomic analysis of the canine oral cavity as revealed by high-throughput pyrosequencing of the 16S rRNA gene. Vet. Microbiol. 162:891–898, 2013. https://doi.org/10.1016/j. vetmic.2012.11.018
Isaiah A, Hoffmann AR, Kelley R, Mundell P, Steiner JM, Suchodolski JS. Character- ization of the nasal and oral microbiota of detection dogs. PLoS One 12:e0184899, 2017. https://doi.org/10.1371/journal.pone.0184899
Wallis C, Marshall M, Colyer A, O’Flynn C, Deusch O, Harris S. A longitudinal assessment of changes in bacterial community composition associated with the development of periodontal disease in dogs. Vet. Microbiol. 181:271–282, 2015. https://doi.org/10.1016/j.vetmic.2015.09.003
Watanabe, K., Hayashi, K., Kijima, S., Nonaka, C., & Yamazoe, K. (2015). Tooth brushing inhibits oral bacteria in dogs. The Journal of veterinary medical science, 77(10), 1323–1325. https://doi.org/10.1292/jvms.14-0193
Pereira, A. M., & Clemente, A. (2021). Dogs’ Microbiome From Tip to Toe. Topics in companion animal medicine, 45, 100584. https://doi.org/10.1016/j.tcam.2021.100584
Giaretta PR, Suchodolski JS, Jergens AE, et al. Bacterial biogeography of the colon in dogs with chronic inflammatory enteropathy. Vet. Pathol. 57:258–265, 2020. https://doi.org/10.1177/0300985819891259
Song SJ, Lauber C, Costello EK, et al. Cohabiting family members share microbiota with one another and with their dogs. Elife 2:e00458, 2013. https://doi.org/ 10.7554/eLife.00458
Bradley CW, Morris DO, Rankin SC, et al. Longitudinal evaluation of the skin microbiome and association with microenvironment and treatment in canine atopic dermatitis. J. Invest. Dermatol. 136:1182–1190, 2016. https://doi.org/ 10.1016/j.jid.2016.01.023
