Puppy gut health shaped by lifestyle and genetics

The gut bacteria diversity in Labradors is influenced by a mix of factors and is formed in the first few months of life, study finds.

The bacteria inside dogs’ guts develop during puppyhood, and are shaped by factors including genetics, household environment, antibiotic use and coat colour, a year-long study shows.

Researchers followed 76 Labrador Retriever puppies as part of the Royal (Dick) School of Veterinary Sciences’ Dogslife project, a large-scale long-term study of canine health.

The finding suggests that the period before four months of age may be particularly important in shaping the puppy’s gut.

Dogslife follows thousands of Kennel Club-registered Labradors across the UK through owner-reported data, with the aim of uncovering environmental and genetic risk factors for health and wellbeing in the breed.

Genetics and environment

Owners submitted puppy faecal samples at four, seven and 12 months of age, alongside questionnaire data, allowing scientists to track how the dogs’ microbial makeup changed over time.

Unlike in humans, in whom gut diversity builds gradually in childhood, puppies showed a diverse microbial mix at three months old, and these changed relatively little through puppyhood.

Although the study found links with factors such as age, sex, coat colour, diet and lifestyle, these only explained a small amount of the differences in gut bacteria seen between dogs.

Most of the variation couldn’t be accounted for, suggesting that genetics and early-life influences are likely to have a much bigger impact on the gut microbiome than previously thought, the team explains.

Antibiotic use

Puppies who had recently received antibiotics showed reduced gut bacteria diversity and shifts in bacterial composition. However, these effects were short-lived and tended to rebound within weeks.

The research team highlights the importance of responsible prescribing in light of these effects.

Coat colour

Coat colour has previously been identified as a risk factor for weight gain in Labradors.

This study has found an association between coat colour and gut microbiota for the first time. The mechanism is not yet understood, but the team suggests that selective breeding for desirable colours may influence metabolism and gut bacteria.

This research was published in Animal Microbiome, in collaboration with colleagues from the Roslin Institute and the University of Manchester.

Owners of Kennel Club-registered Labrador Retrievers can join Dogslife for free and contribute to improving health outcomes for the breed

This work highlights the complex associations between genetics, environment and management in shaping canine gut health, and shows the value of following the same dogs over time rather than relying on one-off samples.
“What surprised us most was how diverse the gut microbiota already was at four months of age, and how relatively stable it remained throughout puppyhood.

This study gives us a much clearer picture of how the gut microbiome develops during a critical stage of a dog’s life. Understanding what shapes the microbiome in early months could open doors to new strategies for supporting digestive health and resilience in dogs as they grow.

Genetics and environment

Antibiotic use

Coat colour

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