Microbiome Monday: Gut Health Differences in Dogs and Cats
By Dr. Keith Weingardt, DVM
While both cats and dogs have complex microbiomes, their differences reflect their distinct dietary needs, evolutionary backgrounds and digestive physiology.
Diet Shapes the Microbiome
One of the most significant differences between feline and canine microbiomes stems from their dietary evolution.
Cats are obligate carnivores, meaning their microbiomes are adapted to digesting high-protein, meat-based diets with minimal carbohydrates. Their gut bacteria are efficient at breaking down animal protein and fat but are less equipped to process plant-based fiber.
Dogs, on the other hand, are omnivores with microbiomes that can handle a more varied diet, including proteins, fats and carbohydrates. Over time, their gut bacteria have adapted to digest starches and fiber more effectively than their feline counterparts.
Microbial Diversity: Dogs Have the Upper Hand
Research shows that dogs generally have a more diverse gut microbiome than cats. Greater diversity is often associated with better resilience and adaptability to dietary changes.
Cats, having a more specialized diet, tend to have a less diverse microbiome, making them more sensitive to dietary shifts or disruptions.
Fermentation and Fiber Utilization
Dogs possess gut bacteria that can ferment plant-based fiber, producing beneficial short-chain fatty acids (SCFAs) that support gut and immune health. While some SCFAs are present in cats, their microbiomes are less reliant on fiber fermentation, as their primary energy sources come from proteins and fats rather than carbohydrates.
Gut Transit Time and Bacterial Composition
Cats have a shorter gastrointestinal tract and a faster gut transit time than dogs. Their microbiota composition is geared toward rapid digestion and nutrient absorption from meat rather than prolonged fermentation.
In contrast, dogs, with their more omnivorous tendencies, have a slightly longer gut transit time, allowing for more microbial fermentation of fiber and plant material.
The Takeaway
Understanding the differences between feline and canine microbiomes is essential for optimizing their diets and supporting gut health. Cats thrive on protein-rich, low-carb diets, while dogs can benefit from a broader range of nutrients, including fiber.
Whether formulating pet foods, probiotics or supplements, keeping these differences in mind ensures better digestive support tailored to each species' unique needs.