It is known that humans are not the only ones who can benefit from brewer’s yeast. They are often found in pet food formulas and treats.
You may be surprised to find “brewer’s yeast” in the ingredient list of cat or dog food.
And maybe you’ve also noticed in pet stores that brewer’s yeast can be sold separately as a supplement to our pets’ diets.
And logically, the question arises, what can brewer’s yeast have to do with pet food?
Today let’s talk about what brewer’s yeast is, whether it should be used, and how necessary it is in the nutrition of cats and dogs.
Table of Content:
Saccharomyces cerevisiae, commonly known as brewer’s yeast is a type of germ yeast.
They have been used for thousands of years to make fermented beverages and foods such as beer, wine, and bread.
Brewer’s yeast is essentially spent yeast left over from the brewing process.
Rich in B vitamins and protein, dry inactive brewer’s yeast can be used as a nutritional supplement.
Unlike bacteria, yeasts are unicellular microorganisms with a nucleus enclosed in membranes.
Consequently, yeasts are classified and belong to the group of unicellular fungi.
The first yeasts originated hundreds of millions of years ago.
Compared to bacteria, more than 1500 species of yeast have been identified to date.
Like bacteria, yeast forms part of the natural microbial flora found in and on animals and humans.
People have used yeast in baking and brewing for centuries, but have also suffered from its effects. For example, because of Candida albicans (thrush), the best known of the yeast inhabitants in the human body.
Brewer’s yeast is a nutritional supplement that can boost energy levels and strengthen the immune system. It is a rich source of:
It is also an excellent source of B vitamins:
In 1883, Emil Hansen was able to isolate and clone the yeast used to produce Carlsberg lager beer.
In this respect, brewers around the world remain indebted to this chemist of the Carlsberg brewery. His scientific approach laid the foundation for what we call modern yeast production and its production to serve breweries large and small.
Brewer’s yeast is also being actively studied in industries other than the animal feed industry.
For example, the aquaculture (aquatic organism farming) and feed industries are studying yeast more seriously and rapidly than our pet food industry. This is because these industries require large amounts of proteins.
However, borrowing their knowledge can benefit us too 👍.
Aquaculture literature reports the following yeast composition:
These values depend on the species of yeast, the substrate on which it was grown, and several other conditions.
The amino acid composition of brewer’s yeast also varies by species and growing conditions, but in general, the results are similar to soybean meal with lower levels of methionine and higher levels of lysine.
Yeast can also contain notable levels of nucleic acids (5% to 11%), which can be seen as beneficial in some circumstances (flavor) and problematic in others (uric acid metabolism in Dalmatians).
Dry brewer’s yeast contains nutrients essential for dogs and cats. It is a protein source rich in amino acids and B vitamins.
Amino acids help your pet build and maintain his or her muscles, bones, blood, organs, immune system, coat, and nails.
As a reminder, there are about 20 different basic amino acids that are commonly found in proteins. Some of them are lysine, histidine, arginine, threonine, and others.
Without proper levels of essential amino acids, protein synthesis is impaired. In addition, B vitamins support brain function, muscle strength, red blood cell production, and digestion.
Although brewer’s yeast may taste bitter to humans, it may be of interest to dogs and possibly cats. These flavors are an important component of pet food.
Pet food manufacturers can also use dried brewer’s yeast in their recipes.
That’s what we’re going to talk about next….
People have trusted brewer’s yeast as a nutritional supplement for centuries.
A few decades ago, pet food companies started using brewer’s yeast to improve flavor.
Turns out, the savory flavor that humans like is also enjoyed by dogs. Regarding the flavor benefits for cats, history is silent on this so far – we haven’t found scientifically proven facts.
Now, however, yeast’s popularity is not just limited to its flavor profile. By introducing one ingredient, the recipe developer can simultaneously control four different feed properties:
Dry brewer’s yeast (brewer’s yeast) is just one of the many available, approved ingredients that a pet food manufacturer may use when formulating a recipe.
First of all, it’s cost-effective! Since liquid yeast is a by-product of most brewers, of course, the supply chain for this ingredient is very stable and consistent.
Brewer’s yeast is also a fairly environmentally friendly by-product of the food industry – there is virtually no waste generation.
You and I get a tasty beer, pets get a protein-rich food supplement. The actual result is a waste-free and environmentally friendly cycle.
Such a simple ingredient beer yeast does a lot, doesn’t it?
It has been said that the two benchmarks for ideal amino acid composition are egg white or milk protein. Perfect nutrition, right?
While yeast is not exactly the same as eggs and milk, they are surprisingly similar.
This makes yeast products a great solution for formulators who are developing high-meat diets and want to provide high protein content.
Actually, brewer’s yeast helps deliver protein to those formulas that contain a higher ash content.
The effects of yeast were unknown until recently.
But now researchers are discovering that yeast may be doing much of the work for animal health.
For years, flavor and protein were the main reasons for using brewer’s yeast in pet foods.
As the industry has learned more about gut health and its impact on overall wellness, it has been discovered that beer yeast can play a big role in this area as well.
There are several reasons for this (according to Petfoodindustry).
First, yeast has compounds called beta-glucans in its cell wall. The innate immune system of almost all animals, from insects to mammals, has receptor proteins that recognize only yeast beta-glucans.
These receptors probably exist because some yeasts are pathogens, so the immune system has learned to recognize beta-glucans to protect itself. But brewer’s yeast is not a pathogen.
Because of this, brewer’s yeast products help keep your innate immune system active without causing inflammation.
It’s sort of like a guard dog resting on your porch. It’s there and alert, but only turns on when needed.
Second, in addition to beta-glucans, yeast contains mannan oligosaccharide or MOS, which helps in two ways.
Lastly, yeast directly supports the health of intestinal cells. These cells are actively dividing, so there is a huge need for DNA and RNA precursors, free amino acids, and B vitamins.
And yeast has just all of that, and it provides food for the intestinal cells.
According to AAFCO (Association of American Feed Control Officials), dry brewer’s yeast must be the result of brewing beer or ale.
Interesting from Murmeo! Recall that there are a number of organizations around the world that develop requirements for animal feed. One of them is AAFCO. More details about these organizations can be found in our materials.
Each ingredient in pet food should serve a specific purpose. For example, it may be used because:
Many ingredients in a pet food recipe can serve multiple functions, and brewer’s yeast is just one example.
“Not all yeasts are the same. They can differ in structure, composition, and function depending on the strain. The researchers’ goal is to find and select the strains that have the best adhesive properties,” says Dr. Francesca Susca of Lallemand Animal Nutrition, Italy.
There are live yeasts that can theoretically be added to animal feed because of their probiotic effects.
Why theoretically, you may ask? Because in the European Union, the use of live yeast in pet food is not permitted (as of 2019).
There is also inactive yeast (dead yeast cells) used as flavor enhancers or as a natural source of nutrients such as B vitamins, amino acids, and minerals.
Inactive yeast can be divided into two different fractions:
1. Yeast extracts, i.e. the soluble fraction of inactive yeast, consisting of more than 60% proteins. They are a valuable source of proteins, nutrients, and minerals. They can also be used as natural flavor enhancers and flavor additives in pet foods.
2. Yeast cell walls are rich in beta-glucans and mannan oligosaccharides, which are well known for their, pathogen binding, and immunomodulatory activity. They can help to balance the microbiota of pets and improve digestion.
Brewer’s yeast is a good source of natural protein, dietary fiber, B vitamins, selenium, and potassium. Although scientific studies are limited, there are some purported benefits of brewer’s yeast for cats and dogs. These may include:
If you look closely at the label of your pet’s food or treats, you may notice the presence of dried brewer’s yeast as an ingredient.
Pet food companies often add dried brewer’s yeast (or other yeast products) to dog and cat food formulas to improve flavor.
Regarding safety, moderate amounts of brewer’s yeast in pet foods are considered safe for dogs and cats.
Interesting from Murmeo! Studies have been conducted regarding the effect of brewer’s yeast on preference in animals. The results showed that dogs prefer diets with yeast. But the attitude of cats to the “beer diet” remains neutral.
Accordingly, keep in mind that adding brewer’s yeast does not guarantee that your pet will be crazy about this meal. Particularly if you have a rather picky eater.
By the way, we have just one of those – it’s our Abyssinian cat. We have to “run after him with a spoon” to feed him.
“If you want more than just an improvement in taste and flavor, it’s best to talk to your veterinarian first,” advises Dr. Michelle Burch, a veterinarian with Safe Hounds Pet Insurance.
“Adding brewer’s yeast to correct underlying problems has a high chance of not curing the disease, and long-term treatment of the disease can make it worse,” she continues.
Good quality pet food should provide complete and balanced nutrition and meet standards (e.g. AAFCO or FEDIAF).
If your pet is nutritionally deficient, your veterinarian may recommend changing your pet’s diet or using supplements.
As a reminder, brewer’s yeast is rich in B vitamins, including thiamine, riboflavin, niacin, pantothenic acid, pyridoxine, biotin, and folic acid.
B vitamins have been shown to support healthy digestion and play an important role in maintaining healthy skin and coat.
“Brewer’s yeast is used for folic acid deficiency, which is commonly seen in chronic disease or inflammation of the upper small intestine,” says Burch.
She adds that vitamin B supplementation can also help reduce intestinal disease and iron deficiency in dogs and cats.
However, keep in mind that brewer’s yeast does not contain B-12, which aids digestion and helps prevent certain types of anemia.
Brewer’s yeast is known to contain approximately 50 percent protein, and in addition, this protein is highly digestible. One study showed that supplementation with brewer’s yeast (Saccharomyces cerevisiae) can have beneficial effects on gut health, boost immune function and reduce inflammation in dogs.
The immunostimulatory properties of brewer’s yeast may be due in part to selenium, an important mineral with antioxidant properties.
Some human studies have shown that brewer’s yeast may help regulate blood sugar levels in diabetic patients due to its high chromium content.
The University of Maryland Medical Center (USA) states that brewer’s yeast is an excellent source of B vitamins and chromium.
B vitamins play an important role in the health of your cat’s skin, coat, and eyes. They aid in the metabolism of fats, proteins, and carbohydrates, supporting your kitty’s energy levels, as well as supporting her liver and nervous system.
Recall that we wrote about carbohydrates in cat diets earlier.
Diane Stein in her book “Natural Healing for Dogs and Cats” says that commercial cat food can be deficient in vitamin B1.
Severe vitamin B1 deficiency can cause seizures, impaired motor coordination, and even death. She also recommends chromium to regulate blood sugar levels in cats with diabetes.
There are several fundamentally different variations of beer yeast sales on the market:
As a reminder, brewer’s yeast for cats is available in liquid, tablet, and powder form. Any of them can be mixed with your cat’s food.
Some veterinarians advise that if you want to use brewer’s yeast as a flea repellent, look for yeast with high sulfur content.
You can buy brewer’s yeast at veterinary clinics, pet stores, and pharmacies. Well, and actually on the Internet on the relevant sites.
As with any dietary supplement for dogs and cats, it is important to read the label carefully and follow proper dosage instructions. Brewer’s yeast is administered orally to dogs and cats in powder and tablet form.
The powder is usually sprinkled on or mixed with food. In commercially prepared food, brewer’s yeast may already be added to it.
If you’re wondering how many milligrams of brewer’s yeast for dogs and cats is considered safe, it will depend on the product itself and your pet’s weight. Talk to your veterinarian about the ideal amount of yeast for your pet.
And don’t forget to be sure to read the instructions on the package!
In general, brewer’s yeast for dogs and cats is considered safe if you buy it from a reputable company and use it according to the instructions on the label.
However, keep in mind that they are only intended for intermittent or supplemental feeding.
According to some veterinarians, brewer’s yeast has a high margin of safety.
Pets that even if they eat too much brewer’s yeast may experience only mild gastrointestinal side effects.
“The most common sign of a beer yeast overdose is an upset stomach with vomiting and transient diarrhea,” veterinarians said.
Keep in mind that many brewer’s yeast formulas contain garlic, which in high doses can be toxic to dogs and cats.
Although only small amounts of garlic are commonly used in pet foods and supplements, caution should be exercised, especially when purchasing supplements from an unknown manufacturer.
If your dog or cat has health problems, consult a veterinarian before feeding your pet brewer’s yeast.
Because brewer’s yeast is rich in certain B vitamins and purines, it may not be suitable for diseases with urinary problems, for example.
Some veterinarians have been known to recommend daily supplements of brewer’s yeast with garlic as a way to keep your cat safe from flea infestations.
However, a 1983 study by the University of California at Davis found that giving dogs 14 grams of beer yeast daily for 5 weeks did not cause a reduction in fleas.
You may have noticed that some companies sell a mixture of brewer’s yeast and garlic for dogs and cats and advertise it as a natural flea’s repellent.
However, there is not yet enough scientific evidence to support this claim.
“Brewer’s yeast supplements have been used to control fleas, but they are questionably effective,” says Dr. Stacey Chocinski Johnson, veterinary expert at Pumpkin Pet Insurance.
“Dogs treated with brewer’s yeast often end up in the veterinary hospital with flea infestations.”
If your cat begins to itch or show other signs of an allergic reaction, stop giving him not only brewer’s yeast, but all yeast products.
Brewer’s yeast toxicity may be related to an animal’s sensitivity to yeast in general or, more importantly, to the preparation of brewer’s yeast for commercial and consumer use.
Keep in mind that brewer’s yeast is a byproduct of the brewing process. However, because of some of the ingredients added to it during commercial preparation, it can be toxic to dogs and cats, up to and including fatal.
Of course, this does not apply to those brewer’s yeast that are specifically designed for animals.
Beer yeast allergy symptoms in cats may be related to sensitivity to yeast products in general or to additives in products for commercial use.
Incidentally, cats are considered to be more sensitive to yeast.
Symptoms associated with yeast allergies in cats may include:
Additional symptoms of ingredient allergies/toxicity:
As the world’s population continues to grow, food production for humans and animals will be more limited by environmental resources. And in turn, the need for high quality protein sources in pet foods will require us to start looking for alternatives.
Specifically, these alternatives must have a small ecological footprint, be sustainable, provide adequate nutrition for the dog/cat, and be well accepted by the animal (aroma and flavor).
And on top of all that, they must be competitive with the economics of current ingredients.
Just yeast can fulfill these needs 🔥.
And let’s try to answer the main question: should cats be given brewer’s yeast as supplements?
If your pet’s diet is balanced and you feed it high-quality commercial feed or natural food, then you probably do not need any supplements.
However, if your pet is on a “mixed” diet (homemade porridge, cooked meat, etc.), then you may need such a supplement.
It should be remembered that brewer’s yeast has a large amount of vitamin B and this can cover their lack of nutrition poor on these vitamins.
And that’s all for today!
If you liked our reasoning about brewer’s yeast in the diet of animals, then for us the best gratitude will be if you share the link to the article with your “cat moms and cat dads” ❤️.