Leaky Gut Syndrome In Dogs

Leaky Gut Syndrome In Dogs 

Leaky Gut Syndrome in dogs is a condition where the mucosal lining and bonds between cells that line the inside of the gut are damaged and openings develop through which fecal matter, toxins, Candida Fungus, and partially digested proteins leak into the blood stream.

The lining on the inside of the small intestine is only one cell thick and is composed of specialized cells called Enterocytes. The inside surface of the enterocytes are covered in a mucus membrane with small hairs called Cilia that extract nutrients from the digested food and transport them into the blood stream where they are distributed throughout the body. The other important function of the Enterocytes is to keep waste matter, toxins, and harmful bacteria, on the inside of the intestine, isolated from the rest of the body, until they are eliminated.


There are a variety of factors that contribute to Leaky Gut but the most damaging ones are grains, potatoes, and high glycemic carbs found in most dog foods.

Dogs are carnivores designed to eat meat, not grain or potatoes. Their Mitochondrial DNA is 99.8% identical to a 20,000 year old Gray Wolf and determines what their body is designed to eat to provide energy for their system. 

We may trick dogs into eating grain and potatoes by adding a meat flavoring but their systems are not designed to deal with the high glycemic carbohydrates as human systems are. The Nuclear DNA, that is manipulated to get a Gray Wolf to look like a Beagle, has nothing to do with the energy system and what the dog is designed to eat. That is determined by the Mitochondrial DNA which is only passed on by the female and has remained constant for tens of thousands of years.

Hanging out with humans, and eating grain, flavored to taste like meat, has caused dogs to adapt a little and increase the amount of Amylase it produces, with is the enzyme that breaks down carbohydrates. Just because a dog will eat something, or their body can digest it, does not mean it is good for them or that it will not affect them negatively. Children can digest sugar but that does not mean it is healthy for them to eat a lot of it.

There are nearly 300 rendering plants in the US that produce over 22 billion pounds of "rendered" protein a year from a variety of dead or euthanized animals and waste meat not fit for human consumption. Someone is buying 22,000,000,000 pounds of this stuff and putting it in dog food as a cheap alternative to expensive meat meals from healthy animals. The drug used to euthanize animals is not destroyed by the rendering process and becomes part of the next food it goes into.

When less expensive vegetable proteins are used in place of animal proteins to cut costs, this increases the possibility of Leaky Gut due to the cumulative effect of the pesticides (Glyphosates) used on them, as well as Lectins which are in all plants, and Mycotoxins (like Aflatoxin B1) that may have developed in the grain when it was stored in hot, humid silos for six to twelve months.

Dairy is another cause of Leaky Gut, as are most chemical preservatives, coloring, and GMO’s. Below is a list of causative factors for Leaky Gut roughly organized with the worst offenders at the top .


Candida Overgrowth (Dysbiosis) - The primary and predominant cause of Leaky Gut. The result of grain, potatoes, sweet potatoes, sugar in any form, and other high glycemic carbs that feed the Candida Albicans Yeast/Fungus in the gut, enabling it to overgrow and overwhelm the beneficial bacteria (which usually keeps it in balance). The fungus attacks the mucosal lining and the joints between the Enterocytes that line the inside of the gut, causing the gut to become porous in areas. 

Antibiotics - kill the beneficial bacteria in the Gut along with the harmful bacteria, but in the presence of sugar the harmful carbs (like the Candida Fungus) grow back faster than the beneficial bacteria creating a state of Dysbiosis, which leads to Leaky Gut.

Chemical Preservatives and Coloring are commonly used and inexpensive preservatives like Ethoxyquin, BHA, and BHT attack the gut lining, as does most synthetic coloring used.

Almost all fish is soaked in the preservative Ethoxyquin before sold to a dog food manufacturer. Manufacturers can say there is no ethoxyquin added or used as long as it was added before they got the fish and they did not add more. Very tricky. 

Topical flea and tick treatments  are very toxic pesticides that attack the gut lining.

Steroids and NAIDS - suppress the immune system and lead to Dysbiosis. Steroids are often given to suppress “Allergies” but in the final analysis, just make them worse. Steroids do not heal Leaky Gut.

Gluten & Dairy - Both Gluten and Dairy cause Leaky Gut in dogs that are sensitive to gluten or don’t have  the enzyme lactase to digest the lactose in dairy.

Mycotoxins,- Mycotoxins are toxic molds that grow on grains and legumes while stored in hot grain silos for months at a time. Aflatoxin B1 is a very toxic mold that affects the balance of bacteria in the gut leading to Dysbiosis.

Lectins - Are the defense mechanisms found in most plants and they attack the mucosal lining weakening it in the absence of additions like probiotics that mitigate their negative impact.

Glyphosate - is a common herbicide used on grain and legumes that damages the beneficial bacteria in the gut eventually leading to Dysbiosis in the absence of prebiotics and probiotics to restore the gut biology.

Heartworm medications and Antihystamines - Harm the beneficial bacteria and lead to Dysbiosis and Leaky Gut.

Repeated Vaccination - introducing something the body has already developed antibodies to creates an immune response that causes inflammation of the gut lining.


This is due in large part, I believe, to the medical professions tendency to rely on the symptoms of a problem to identify it. Without a clear set of symptoms they could directly link to Leaky Gut, it was natural to conclude that either it didn’t exist or was not important enough to investigate further.

Although there is no concrete test for Leaky Gut, the most prevalent toxin to leak through a porous gut is the Candida fungus which is an accurate indicator that Leaky Gut exists. It spreads through the body in the blood stream and is referred to as Systemic Candida. Having a fungus coursing through the blood stream causes no end of problems most of which are skin related. If your dog is constantly scratching, licking its paws, biting its tail, scooting on the floor, has dull, dry hair, or yeasty ears, it is almost certain that it has Systemic Candida as a result of Leaky Gut.

Any attempt to treat the symptoms without healing Leaky Gut first are fruitless. Leaky Gut must be healed first, then the process of eliminating the Candida fungus from the blood stream can begin.

This is accomplished by eliminating all forms of sugar and high glycemic carbs that feed the Candida Fungus it until it is so weak the immune system can finish it off.

This can take from a few weeks to a few months and it needs to happen gradually because the Candida fungus releases a toxin as it dies off that can be quite uncomfortable for the dog if it happens too fast. 

Using an anti-candida medicine is too hard on the liver.

Claiming the dog can digest those ingredients is missing the point completely. Digestible or not, they damage the gut which causes a host of health problems.

The following sequence of events shows why it has been so difficult to connect Leaky Gut to the broad range of problems it creates.

Your dog eats a diet that includes high glycemic carbs (grain, potatoes, etc) which cause Candida fungus in the gut to overgrow and overpower the beneficial bacteria (Dysbiosis) and eventually cause gaps between the cells (Enterocytes) that make up the gut lining and fecal matter begins leaking into the blood stream.

During digestion partially digested pieces of protein (random lengths of amino acids) leak through the gaps into the blood stream. The immune system sees them as invading pathogens, creates antibodies, attacks them, and remembers them in case they return, which of course they do.

The Candida fungus also leaks into the blood stream and, as it gets more sugar from the grain, potatoes, and carbs in the diet, it multiplies and spreads through the blood stream to the entire system. Now the dog has a fungus in its blood stream, a condition known as Systemic Candida.

Antibiotics are usually prescribed at some point which kill the beneficial bacteria that usually keeps the Candida fungus in check and the Leaky Gut condition gets worse because the pathogenic bacteria regenerate faster than the good bacteria under normal conditions.

As more and more fecal matter leaks into the blood stream the immune system becomes overwhelmed, exhausted, and hyper-sensitive which leads to an autoimmune response where it attacks its own organs.

Partially digested protein continues to leak into the blood stream and the immune system attacks escalate which is interpreted as an allergy to that protein. Now they have a symptom (an allergic reaction) but the cause is not the meat protein as is commonly assumed, and long term solutions based on that premiss are ineffective.

The problem is not the protein but the Leaky Gut condition that  allowed the protein to leak into the blood stream causing an immune response. The protein is not in itself an allergen. ANY protein that leaks into the blood stream will trigger an immune response. Fix the Leaky Gut and the dog can eat that protein without a problem going forward. Changing to a novel protein without fixing Leaky Gut will eventually create an immune response to that protein as well.

All this time the Candida fungus is coursing through the blood stream causing no end of skin problems and ear infections that are making the poor dog miserable.

The autoimmune response continues causing system wide inflammation, overweight, and widespread discomfort and your dog does not have the words to tell you where it hurts.

Few, if any, would imagine that all of these health problems are caused by the same problem, Leaky Gut, much less believe that the most common cause of the problem is diet, especially one with high glycemic grains and potatoes - ingredients commonly used in the vast majority of dog foods on the market - but that is the sad reality.




Some of the causes like Glyphosates, are almost unavoidable to some degree, given the food supply chain in this country, and the amount of pesticides we dump on our food crops. 

Lectins, are in most plants and Mycotoxins are toxic molds that tend to grow on grain and food stored in hot, humid silos. Eliminating grain from the food greatly reduces a main source of Mycotoxins one of which is the harmful Aflatoxin B1.

Some of the causative factors, in limited amounts, can be handled by a healthy system. The dog can generally be kept healthy, and Leaky Gut avoided, by feeding a good quality, well designed, nutritionally balanced, high protein dog food free of high glycemic carbs like grain and potato.

Protein content should be between 30% and 40% and be over 90% animal protein versus vegetable protein. It should be meat meal from healthy animals (which is three times the amount of protein than whole meat), and eggs (which have every essential amino acid and are easily digestible).

Carbohydrates should be low glycemic, Gluten free, with resistant starch, such as Cassava Root flour (Tapioca), and have insoluble fiber such as peas to form POSTbiotics in the colon that feed the beneficial bacterias.

Fat should be animal fat.

The Protein, Fat, and Carbs should be in equal amounts on a calorie rated basis.


To heal and restore the gut biology to a healthy state it is important to add probiotics, and prebiotics to feed the probiotics.


Adding digestive enzymes help ensure complete digestion of the proteins into individual amino acids that the body accepts and uses to rebuild. When partially digested proteins (random lengths of amino acids) get through the gut wall into the blood stream the immune system attacks them and creates an allergic reaction to the protein.

We know this from first hand experience because fifteen years ago we created a dog food that followed these exact recommendations and has successfully healed Leaky Gut and prevented it from developing in thousands of dogs over the last fifteen years.

While I cannot say to what degree things like Lectins and Glyphosates play a role in causing Leaky Gut, I know what the predominant causative factors are because when we eliminated them, Leaky Gut healed as did Systemic Candida - regardless of the degree that other causative factors may have been present.

Once Leaky Gut is healed and the system is restored to balance  you will be amazed at how quickly vibrant health returns. Dogs are extremely resilient when fed a healthy, grain free, balanced diet with equal calories of animal protein, animal fat, and low glycemic carbs (especially those with resistant starch like Tapioca, and insoluble fiber like peas, that perform as POSTbiotics and feed the beneficial bacteria in the colon. The additional support of PREbiotics, PRObiotics, POSTbiotics, and Digestive Enzymes are crucial to keep the system healthy and prevent Leaky Gut and Systemic Candida going forward.

 Written by Richard Darlington  Jan 18, 2023




HEALING LEAKY GUT SYNDROME IN DOGS https://brothersdogfood.com/blogs/blog/healing-leaky-gut-syndrome-in-dogs

Leaky Gut Syndrome in Dogs https://brothersdogfood.com/blogs/blog/leaky-gut-in-dogs

FOOD ALLERGIES Caused by Leaky Gut 


Probiotics and Beneficial Bacteria in Dog Food




[1] Less is more? Ultra-low carbohydrate diet and working dogs' performance


[2] Altered Immunity & Leaky Gut Syndrome

Dr Zoltan P Rona MD, MAc



In vitro fermentation and prebiotic potential of pigeon pea (Cajanus cajan (L.) Millsp.) flour


[4] Dogs Naturally Magazine


[5] Wiley Online Library

Cassava-enriched diet is not diabetogenic rather it aggravates diabetes in rats.


 [6] Dog Food Advisor

Are High Protein diets good for overweight dogs?


 Dog Food Advisor

Best Dog Foods for Weight Loss


 Dog Food Advisor

Best Dog Foods for Allergy