The Health Benefits of Probiotics For Cats & Dogs

On November 10, 2013 by AntheaAppel

probiotics for pets“All disease begins in the gut” – Hippocrates

The microorganisms that are found in your cat’s and dog’s digestive tract are a collection of both “good” and “bad” bacteria, fungi, protozoa, and viruses. Since 80% of the immune system is located in the gut it’s a good idea to keep a proper balance of the intestinal microbiota so that the animal’s immune system continues to function well.

Any discussion of probiotics need to mention the Russian biologist Elie Metchnikoff (1845-1916). He is credited with discovering the importance of white blood cells. Before his discovery, doctors believed that WBC were guilty of spreading disease throughout the body. Metchnikoff noticed that peasants in his area were healthier than city dwellers. Somehow he linked the robust health of the peasants to the eating of fermented foods. He reasoned it was the bacteria in the fermented food that were keeping them healthy.

Metchnikoff is known as “the father of natural immunity.” He was the first to coin the phrase “probiotics” and is quoted for saying death begins in the colon. He understood that “good bacteria” must outnumber “bad bacteria” and there must always be a balance for a healthy GI tract. In 1908, Metchnikoff and Paul Ehrlich were jointly awarded the Nobel Prize in Physiology and Medicine “in recognition of their work on immunity.”

The Microbiome Function

The microbiome has many functions: It helps to break down food to liberate nutrients. It also helps to manufacture several vitamins, like, B-vitamins and vitamin-K. The good bacteria nourish the enterocytes by producing short-chain fatty acids, predominately acetate, propionate, and butyate, which maintains the integrity of the intestinal lining. This helps to prevent leaky gut syndrome and inflammation throughout the body. The microbiome also acts as a detox organ and any imbalances will stress the liver, which is also a detox organ. Interestingly, the microbiome in the gut affects brain chemistry and structure. Studies in both animals and humans are finding important connections between gut bacteria and the brain that influence emotions, including psychological disorders like anxiety and depression.

If “bad” bacteria overrun your pet’s digestive tract it can open the door to GI-related disorders, such as, poor food absorption, intermittent or chronic diarrhea, and constipation. It can also lead to some serious conditions like leaky gut (dysbiosis), which means your pet can absorb partially digested amino acids and allergens into their bloodstream. This can result in a slew of other health problems from allergies to disorders of the immune system.

You may ask, how do I keep the good and bad flora in balance? Or how do the bad bacteria get out-of-hand in the first place? Things go awry in the GI tract from antibiotics, processed pet food, glysphosate in the food supply and environment, vaccinations, the use of steroids, like, prednisone, surgery, and chronic illnesses. And, then there are the emotional stresses, such as, travel, loneliness, being placed in a boarding kennel, moving to a new home, and the arrival of a new pet (or, a baby) to the home.

Bad vs Good Bacteria

What do we mean by “good” or “bad” bacteria?

Most bacteria are classified into two categories: Gram-negative, or Gram-positive. The difference between the two types of bacteria, is, Gram-positive has a cell wall composed of thick layers of peptidoglycan (a macromolecule composed of sugars and amino acids) and have an outer membrane. Gram-negative has a cell wall with a thin layer of peptidoglycan, but the outer membrane is absent. Both Gram positive and Gram negative bacteria produce exotoxins, but only Gram negative bacteria produce endotoxins. If these toxins are released into the bloodstream it can cause illnesses and damage to organs and tissues.

Examples of Gram positive bacteria would be Staphylococcus and Streptococcus. Both are part of the normal microbiota, but only become a problem when there’s an overgrowth or a weakened immune system. Examples of Gram negative bacteria are Haemophilus influenzae, responsible for sinus infections and pneumonia, and N. gonorrhoeae, the pathogen which causes the sexually transmitted disease gonorrhea.

Gram positive bacteria are more susceptible to antibiotics due to the lack of an outer membrane. Since Gram negative bacteria contain an outer membrane they are less susceptible to antibiotics. Therefore, Gram negative bacteria are more pathogenic compared to Gram positive bacteria.

The problem with antibiotics

Antibiotics not only kill the “bad” bacteria, but it also kills the “good” bacteria. I put the word bad in quotations because it is natural for our pets (and humans too) to have “bad” flora in our body. For example, us humans have hemolytic streptococcal, pneumococcal, meningococcal, and other pathogenic bacteria, diphtheria bacilli, are found in the mucus of the mouth, pharynx, and nose. And the reason we’re not walking around with strep throats, meningitis, or pneumonia all the time is because a healthy body will keep these bacteria in check.

It is estimated that several thousand bacterial phylotypes inhabit the human colon. Recent studies have estimated that approximately 200 bacterial species and 900 bacterial strains reside in the canine jejunum, whereas several thousand phylotypes are thought to be present in fecal samples of dogs and cats. Ten to 12 different bacterial phyla are routinely identified in the mammalian GI tract. (Intestinal Microbiota of Dogs and Cats: a Bigger World than We Thought ~ Jan S. Suchodolski, med vet, Dr med vet, PhD)

Both humans, cats, and dogs have Escherichia coli (E.coli) in their guts. However, humans carry more of the drug-resistant E.coli than dogs and cats, but because of the close interaction of humans and their companion animals, people are now passing this drug-resistant bacteria to their pets. And we can thank the over-use of antibiotics for the creation of drug-resistant strains of bacteria.

After a bout of antibiotics, the first bacteria to grow back is the negative-gram or the more pathogenic bacteria. A few years ago, a friend of mine took a very strong antibiotic for a gum abscess, which I felt was unnecessary. The dentist had already cleaned out the abscess and all that was left to do was to allow the body to naturally heal it. Well, he took the antibiotic anyway. Well, ten days later he was doubled over in gastric distress with cramps and non-stop diarrhea. This is what happens: The bad bacteria come back first and the body reacts by expelling the toxins. The bad news is it can take four years of an aggressive probiotic protocol to replace the good flora in the guts. But even then, it will never be 100% again…maybe 80% to 85%, but never 100%. Read the research here.

Early evidence from my lab and others hints that, sometimes, our friendly flora never fully recover. These long-term changes to the beneficial bacteria within people’s bodies may even increase our susceptibility to infections and disease. Overuse of antibiotics could be fueling the dramatic increase in conditions such as obesity, type 1 diabetes, inflammatory bowel disease, allergies and asthma, which have more than doubled in many populations. ~ Martin Blaser of New York University’s Langone Medical Center

This is why you have to be careful with antibiotics. If you think doctors prescribe too many antibiotics to people, I can assure you, our animals are given these drugs at an even higher rate. And, the health problems for them can be devastating. For example, Metronidazole, a common antibiotic drug given to dogs can cause a major disruption in intestinal metabolism (bile acids, tryptophen) for at least 4 weeks (See Study). It’s probably much longer than that, but in the study they only looked at the results for 4 weeks. In human studies, it was shown Matronidazole disrupted the gut microbiota for 4 years. So, it may be that long in our dogs, too.

It’s not just antibiotics that can interrupt the microbiome, but also non-steroidal anti-inflammatory drugs (NSAIDs), proton-pump inhibitors, antidepressants, and laxatives.  Research analysis has shown “bacteria in the gastrointestinal tract reflect the combinations of medications that people ingest.” In other words, just by looking at the bacteria in the stool they could tell what medications the people were consuming (See Study). In February 2021, a new study published in the Journal of Veterinary Internal Medicine by the Universities of Georgia, Minnesota, & Texas A & M found 83% of dogs receiving NSAIDs acquired stomach or intestinal damage (See Study).

Feline gastric disorders + meds = trouble

Recently, they have found a link between Inflammatory Bowel Disorder (IBD) and GI Lymphoma in cats. IBD occurs when a collection of gastrointestinal disorders ultimately cause an increase in the number of inflammatory cells in the lining of the digestive tract. Symptoms of IBD includes chronic diarrhea and/or vomiting, which can result in inflammation and scar tissue in the lining of the intestine. These changes may then evolve to cancerous cells and progress to lymphoma of the GI tract (See Study).

The typical treatments for feline IBD involve steroids, antibiotics, and other toxic drugs that can destroy the healthy bacterial balance in your cat’s digestive system. This will eventually make the bowel disorder worse and set the stage for a life-threatening disease like GI lymphoma.

In the blog I wrote on feline IBD, I mentioned the importance of probiotics for healing the gut. A 2014 study showed that in inflammatory bowel disease there is a decrease in Firmicutes and Bacteroidates and an increase in Proteobacteia. This imbalance of bacteria leads to susceptbilities in the innate immune system.

What are the other benefits of probiotics?

Research has shown a reduction of the concentration of cancer-promoting enzymes and/or putrefactive (bacterial) metabolites in the gut.

~ Prevent and alleviate unspecific irregular complaints of the GI tract in healthy people (animals, too).

~ Prevention or alleviation of allergies and atopic diseases in infants.

~Prevention of respiratory tract infections (common cold; influenza) and other infectious diseases as well as treatment of urogenital infections.

~ Preliminary evidence exists with respect to cancer prevention; so-called hypocholesterolemia effects (lowering cholesterol); improvement of mouth flora and caries prevention; prevention or therapy of ischemic heart diseases; amelioration of auto-immune diseases (e.g., arthritis).

Healthy animals benefit from probiotics too

You don’t have to wait for your cat or dog to experience gastrointestinal distress to give probiotics. Instead, it should be part of their daily supplementation. As a matter of fact, some holistic vets consider probiotics the missing “nutrient” from our pets diet.

A study showed that when healthy dogs were fed a food supplemented with Lactobacillus acidophilus there was an increased number of fecal lactobacilli and a decreased number of the harmful clostridial organisms (see Study).  As a result, there was a significant increase in Red Blood Cells, hematocrit (Hct), hemoglobin concentrations, neurophils, monocytes, serum IgG, and reductions in Red Blood Cell fragility and serum nitric oxide (NO), which is a marker for inflammation. Thus, the bacterium L. acidophilus has the potential to help balance the microbiome to enhance intestinal health and improve immune function in dogs.

In another study, the beneficial bactericum Lactobacillus acidophilus was given to 15 healthy adult cats. As a result, populations of the harmful fecal bifidobacteria, clostridium spp, and Enterococcus faecalis were decreased. Plus, the Granulocyte phagocytic activity and Eosinophil numbers increased. And, Red Blood Cells fragility and plasma endotoxin concentrations decreased (see Study).

So, even healthy animals can benefit from probiotics.

But not any probiotics will do

It’s important for the animal to get an adequate amount of gut bacteria. So, how many Colony-Forming Units (CFUs) or viable bacteria do animals need?

5 – 10 x 109 CFUs – People

1 x 108 CFUs – Animals

Not only do cats and dogs have a lower number of gut flora than humans, but they also require different strains of gut flora. For humans, the most common probiotic microorganism are species to the genera Lactobacillus and Bidobacterium; and for animals, it is Bacillus, Enterococcus, Lactobacillus, Aspergillus, and Saccharomyces. So, it’s not a good idea to give probiotics that are intended for humans to our pets. And the ones that I’ve seen sold in pet stores are not the kind of probiotics I would recommend either. Not only are they often of poor quality, but many of them are dairy-based. First of all, dogs and cats lack the enzymes to digest lactose. Second, yogurt, kefir, and other dairy-based probiotics do not have the sufficient number of live bacteria to survive the extremely acidic stomachs of a carnivore (pH 1-1.5, akin to battery acid).

Soil based probiotics are the best (SBO)soil based probiotics for pets

Have you ever seen your dog or cat in the yard pulling up grass or plants by the roots and then eat it? Not only are they benefitting from the chlorophyll in the plants, but the dirt around the roots and on the plant are beneficial, too. Sometimes you’ll even see dogs lick the dirt for the same reason.

Unlike lactic acid and bifidobacteria (which are pre-biotics available in fermented food), most of the beneficial bacterial strains found in productive soil are extraordinarily hardy. They can survive heat, shock, and stomach acid, and most importantly they thrive in the environment that makes up the gut.

According to Dr. Karen Becker, DVM, the following three things is what you need to look for in a good SBO probiotic:

1. It should contain 10 or more strains of beneficial bacteria. Based on a few studies, multi-strain probiotics appear to be more efficient than using a single-strain
2. Each serving should contain a minimum 20 million beneficial bacteria – the higher the number, the better
3. It should be GMP certified to assure the viability, potency, and purity of the product

Before you buy probiotics for your cat or dog, there are other things to keep in mind. First, just by looking at the label will not tell you how active the bacteria strains are in the product. In 2011, a study was done on 25 commercial Animal Probiotic products. They found 7 products that had misspelled the microbe names. I don’t know about you, but for me, I don’t found it particularly reassuring to see misspelling on a product label. 4 products didn’t even bothered to list what specific microbes they contained. 10 products did not list expected CFUs. Only 4 of the 15 products that did list CFUs met label claims. And, only 2 out of the 25 products had proper label and met label claims.

Last, but not least, diet

Many gastro-intestinal problems stem from your pet eating a commercial processed diet. Any food that comes out of a bag, a box, or a can, is processed. These foods are cooked, and over-cooked, to the point of being “dead.” What I mean by “dead” is the meat used for pet food has no essential amino acids, no live enzymes, and most of its micronutrient content significantly reduced.  That’s why pet food manufacturers have to add synthetic nutrients (which just can’t replace the real thing). Food without any “life” is more difficult for the digestive system to break down. This takes a big strain on the colonies of good bacteria as they expend themselves in an effort to find and assimilate the small amount of nutrient value.

A 2017 study found: “The gut microbiota of dogs is significantly influenced by diet type (i.e., natural diet vs commercial feed). Specifically, dogs fed a natural diet have more diverse and abundant microbial composition in the gut microbiota than dogs fed commercial feed.” (Gut Pathog, 2017)

For this study, a natural diet was made up of 90% raw meat/10% vegetables (see Study).

And, don’t forget commercial pet food is full of preservatives. As I mentioned on another blog, preservatives are like “hidden antibiotics” because basically they’re meant to kill bacteria, including what’s in the gut.

The best diet for a strong immune system and good digestion is to feed your cat or dog is raw meaty bones and organs full of live enzymes. Grass-fed, organic meats is the best, but if you can’t afford them and you have to buy the regular meat at the supermarket (which comes from farm-factory animals) then double check on the products label whether the meat contains antibiotics.

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