Study highlights canine microbiome diversity around the world
Most studies look at the microbiome of dogs in veterinary centres, which live very different lives to unowned dogs.
A new study has sampled the microbiomes of dogs across different geographical populations to gain greater population diversity in studies of canine microbiomes.
Analysing the faecal microbiomes from dogs in South Africa, India and Laos, researchers wanted to ascertain how different the microbiomes from different areas were, and also to compare the results with microbiomes from ancient dog populations, obtained from fossilised dog faeces.
Author of the study, Karthik Yarlagadda, explained: “A lot of the studies look at how different diets affect dog microbiomes. Although they are extensive, they work with dogs in veterinary centers, which lead a very different life from dogs that don’t live as pets.
“It’s similar to how studies on the microbiomes of humans have been focused on people who live in cities and eat processed foods.”
Researchers collected faecal matter from pet dogs in South Africa, stray dogs and shelter dogs in India and village dogs in Laos. In each location the different dogs each had different diets. The shelter dogs' diet consisted of rice, lentils, yoghurt and dog food, while the stray dogs scavenged for human leftovers.
In Laos, the village dogs ate local agricultural products, such as maize, corn, bamboo, sticky rice and fish from nearby rivers. In South Africa, the dogs more than likely ate commercial dog food.
Kelly Swanson, professor of animal and nutritional sciences, explained the purpose of the study: “Most of our previous studies have looked at animals that come into a vet clinic or are housed in a research facility; they are vaccinated and eat food that is processed.
“But that is different from animals, like the ones in Laos, that live outside and have a variety of environmental exposures. By carrying out these studies, we can learn what is considered “normal” for different populations around the world.”
Analysis found that although the microbiomes differed between populations, they functioned the same, with different microbiomes fulfilling the same metabolic function.
“For example, dogs that were consuming dairy in the South African and Indian populations had different Lactobacillus species that were probably involved in the same pathway,” said Yarlagadda.
In comparing the samples with ancient microbiomes from fossilised dog faeces, researchers found that the microbiomes from non-US populations resembled the ancient microbiomes more closely, providing a novel insight into the effect of industrialisation on faecal microbes.
Published in Proceedings of the Royal Scoiety B: Biological Sciences, the study can be read here.
Veterinary practices are being urged to help owners safely dispose of any unused and expired pet medicines - not just antibiotics - during November's Animal Medicines Amnesty. 
