Ignore This 'Expert' Advice for a Healthier Gut

Analysis by Dr. Karen Shaw Becker

how to improve gut health in dogs

Story at-a-glance

  • To improve your dog’s gut health, first and foremost, don’t follow the advice of the anti-fresh feeding movement
  • Those who engage in fearmongering about the “dangers” of fresh diets spread misinformation, including that fresh pet food is loaded with salmonella; in reality, it’s ultraprocessed pet food that has a history of recalls for pathogens
  • Thankfully, pet health experts and advocates with a genuine interest in keeping your pet’s microbiome healthy are steadily building a body of research on dietary influences that suggests dogs (and cats) eating fresh food have healthier guts than pets fed processed diets

Unfortunately, even many veterinarians who recognize the importance of a balanced microbiome in dogs have a bias against raw diets, and frequently mention the dangers of salmonella in raw pet food. The truth is, they are either misinformed or ignoring data on the types of pet food most commonly contaminated by salmonella (ultraprocessed kibble), or that research shows that animals fed fresh diets have healthier gut microbiomes.

Sadly, lack of education about pet nutrition fundamentals is a widespread problem in most veterinary schools and veterinary practices across the U.S.

The Demonization of Fresh/Raw Pet Food

About five years ago, the head of the FDA Center for Veterinary Medicine openly admitted to me and the rest of the attendees at an AAFCO meeting that the agency would be heavily focused on testing raw pet foods for the foreseeable future.

The FDA’s decision to target raw diets wasn’t in response to customer complaints or ill dogs or recalls or even the random discovery of contaminants. It was an offensive strategy designed to tap the brakes on this fast-growing segment of the pet food industry, as well as to find a problem to highlight to sow seeds of doubt and fear among consumers (and naïve veterinarians).

Thanks to the constant fearmongering by processed pet food advocates (a group that obviously includes the FDA) about the dangers of salmonella in raw pet food, many pet parents remain concerned about feeding raw foods specifically because raw meat can contain salmonella bacteria. The reality is that pathogen contamination has historically been a problem associated with processed diets — not fresh pet food.

Most recalls involving potentially pathogenic bacteria over the last several years have involved kibble:

types of pet food recalled for pathogenic bacteria

What many pet parents don’t realize, and the anti-raw movement won’t admit, is that salmonella can be found in up to 36% of all healthy dogs and 18% of healthy cats regardless of the food they consume. Many pets harbor these bacteria as a part of their normal gastrointestinal (GI) flora and naturally shed salmonella organisms in feces and saliva.

All non-typhoid salmonella species are ubiquitously present in the environment and reside in the GI tracts of many animals, including pets. Most human salmonellosis cases are acquired through ingestion or handling of contaminated dry pet foods and treats — not raw meat. Here's what you need to know about salmonella:

Dry food and raw food can certainly harbor salmonella, so awareness and proper home hygiene are important, regardless of the type of pet food you feed.

Regardless of what food you feed your pet, animals can naturally harbor salmonella that can be a risk to humans, especially if you or a member of your family is immunocompromised.

The raw meat used in many commercially available raw food diets is human-grade, USDA-inspected and no different from the steak and chicken purchased for human consumption from a grocery store. It should be handled with the same safety precautions you use when you prepare meals for your family. It's all the same meat.

Your kitchen counters, bowls, cutting surfaces and utensils should be disinfected whether the raw meat is intended for your pet or human family members.

About half of the commercially available raw diets on the market are sterile, meaning devoid of all bacteria, because they have been treated with high pressure pasteurization (HPP).

All commercially available pet foods sold in the U.S., including all raw and fresher food brands, must comply with the FDA’s zero tolerance policy for potentially pathogenic bacteria, so all pet food companies should have a protocol in place to batch test their products for safety.

Common Sense Tips for Feeding Raw

The FDA offers the following tips to prevent infection when feeding raw (none of which will come as a surprise to anyone who regularly handles fresh food):1

  1. Thoroughly wash your hands with soap and water (for at least 20 seconds) after handling raw pet food, and after touching surfaces or objects that have come in contact with the raw food.
  2. Thoroughly clean and disinfect all surfaces and objects that come in contact with raw pet food. First wash with hot soapy water and then follow with a disinfectant. You can also run items through the dishwasher after each use to clean and disinfect them.
  3. Freeze raw meat and poultry products until you are ready to use them, and thaw them in your refrigerator or microwave, not on your countertop or in your sink.
  4. Carefully handle raw and frozen meat and poultry products. Don’t rinse raw meat, poultry, fish, and seafood. Bacteria in the raw juices can splash and spread to other food and surfaces.
  5. Keep raw food separate from other food.
  6. Immediately cover and refrigerate what your pet doesn’t eat or throw the leftovers out safely.
  7. If you’re using raw ingredients to make your own cooked pet food, be sure to cook all food to a proper internal temperature as measured by a food thermometer. Thorough cooking kills Salmonella, L. monocytogenes, and other harmful foodborne bacteria.
  8. Don’t kiss your pet around its mouth, and don’t let your pet lick your face. This is especially important after your pet has just finished eating any type of pet food.

Bottom line, follow the same safe handling precautions regardless of what you feed your pet, and be assured that responsible raw food companies perform due diligence to control potential pathogenic bacteria in a variety of nontoxic ways, including using phage technology, fermentation and lot/batch testing to ensure each batch of product is safe for consumption.

Studies Show Raw Fed Pets Have Healthier Gut Microbiomes

Microbial ecologist Dr. Holly Ganz founded AnimalBiome after learning through her research that many pets with chronic health conditions have poor gut health, detected by looking at the composition of their gut bacteria. During my interview with her, I asked Dr. Ganz how she was able to distinguish an animal with an unhealthy gut from one with a healthy gut.

“Sometimes it turned out to be very obvious,” she answered. “We’ve found in many cats and dogs with chronic digestive problems that they have really depleted compositions of gut bacteria. We’re using sequencing to look at that.

Through my work with the Kittybiome project, we began interacting with people who were very passionate about raw feeding — the fact that cats are obligate carnivores, and many commercially available diets aren’t biologically appropriate for them. We could actually see the benefit of raw diets as we analyzed the composition of gut bacteria.

We could see the difference in microbiomes between the sick cats and the cats eating raw diets.”

I’ve talked to other researchers, as well, who were able to confirm what Dr. Ganz has found, which is that animals eating fresh food have a more diverse microbiome.2 You can visit AnimalBiome to learn more about Dr. Ganz’s work and microbiome restorative therapy.

More Evidence of the Benefits of Raw Diets to Gut Health

A 2017 study by researchers in the Department of Animal Sciences at the University of Illinois also revealed how different types of diets affect the gut bacteria of dogs.3 According to the study authors, the objective of the 28-day project was to determine fecal microbiota and metabolite concentrations in 8 adult dogs fed 4 different diets that included 2 lightly cooked diets from Freshpet, a raw Freshpet diet, and an extruded diet (Purina Dog Chow).

The study results showed there are indeed differences in gut bacteria depending on what diet dogs are fed. The researchers observed that the mildly cooked and raw diets were generally higher in protein and/or fat and were more digestible than the extruded diet, and also reduced blood triglyceride concentrations.

Other research on how diet impacts the canine gut microbiome has provided better insight into the benefits of feeding species-specific diets to dogs. For example, a 2017 Italian study compared the influence of a raw meat and vegetable diet vs. an extruded diet in 8 healthy Boxers.

The study authors concluded that feeding a raw diet “… promoted a more balanced growth of bacterial communities and a positive change in the readouts of healthy gut functions in comparison to [an extruded] diet.”4

In a New Zealand study of 15 adult dogs, the researchers discovered that the dogs fed a raw red meat diet showed higher levels of digestibility of protein and energy than dogs fed kibble. They also produced a smaller volume of poop with lower levels of fecal volatile fatty acids.5 As for gut bacteria, the study authors noted that:

“Diet significantly affected 27 microbial families and 53 genera in the faeces. In particular, the abundances of Bacteriodes, Prevotella, Peptostreptococcus and Faecalibacterium were lower in dogs fed the meat diet, whereas Fusobacterium, Lactobacillus and Clostridium were all more abundant.”

The shift in the microbiota correlates to protein and fat digestibility in the dogs. By understanding the relationship between a dog’s microbiome and digestibility of the food consumed, we gain insight into the influence of diet on the overall well-being of pets.

Interestingly, the amount of healthy, indigestible fiber included in raw food diets is also a determining factor in the quantity and diversity of gut microbes. So far, all the raw food research suggests a small amount of fiber (in the form of indigestible plant roughage) is important for building a healthy microbiome, and the diets that do not include fiber create less healthy microbiota.

For this reason, I’m not a proponent of “prey model” type meat, bone, and organ diets, as research continues to demonstrate animals have a healthy microbiota when low glycemic veggies are added in.

The Best Way to Nourish Dog’s Microbiome

While there are many environmental and lifestyle factors that influence your dog’s gut health, the diet you feed has a direct effect on the microbial diversity of his or her microbiome and is the single most important factor in preventing illness and maintaining wellness.

If you haven’t already, I recommend transitioning your pet away from “fast food” (kibble), and instead feeding a nutritionally optimal, species-specific diet, which means food containing unadulterated, high-quality animal protein, moisture, healthy fats, and fiber, with low to no starch content.

If you can’t afford to feed exclusively fresher foods, then add as much minimally processed food to the bowl as possible, whether that’s a few meals a week, or swapping 10%-50% kibble for fresh food. The more you can diversify the types of proteins and brands you feed the healthier your pet’s microbiome will be.

A nutritionally complete raw or gently cooked homemade diet is the top choice for pets, but only for those pet parents who are committed to doing it right. If you don't want to deal with balancing diets at home, choosing to feed a pre-balanced, commercially available raw food produced by a company you trust is a good alternative.

And be sure to incorporate probiotics, fermented veggies, and a variety of fresh foods into your pet's diet, too. Blueberries, chia and hemp seeds in coconut oil, raw pumpkin seeds and kefir can provide your furry family member with a variety of nutrition and flavors. Swapping ultraprocessed pet treats for real food additions is the bare bones minimum recommendation if you aren’t able to improve the quality of your animal’s base diet.