The type of yeast on a dog is mostly Malassezzia. Malassezia is a type of single-celled yeast that naturally inhabits the skin of dogs, playing a role in maintaining skin health. However, when this yeast grows out of control, it can lead to skin infections and other issues. In this article, we will discuss the pathology of Malassezia in dogs from both Western and Traditional Chinese Medicine (TCM) perspectives.
Let’s Learn More About Malassezia
Malassezia is a genus of fungi that includes several species of single-celled yeasts. These yeasts are lipophilic, meaning they have a preference for lipid-rich environments, such as the skin of dogs. This fungi uses lipids as a primary nutrient source for their growth and survival. They obtain lipids from the host’s skin, specifically sebum, which is an oily substance produced by sebaceous glands to moisturize and protect the skin. Sebum is composed of various lipids, including triglycerides, fatty acids, wax esters, squalene, and cholesterol.
To obtain and metabolize lipids, Malassezia produces extracellular enzymes, mainly lipases and phospholipases, which break down the complex lipids in sebum into simpler forms that can be absorbed and utilized by the yeast cells. Lipases cleave the ester bonds in triglycerides and wax esters to release free fatty acids and glycerol, while phospholipases hydrolyze the ester bonds in phospholipids to produce free fatty acids and other by-products.
The released free fatty acids can then be transported across the cell membrane of Malassezia and used as a source of energy or as building blocks for the synthesis of new cellular components. The metabolism of lipids is essential for the growth, reproduction, and survival of Malassezia on the host’s skin.
It’s worth noting that the activity of lipases and phospholipases produced by Malassezia can also contribute to skin irritation and inflammation, as the by-products of lipid breakdown, particularly free fatty acids, can disrupt the skin’s natural barrier function and cause local immune responses. This is one of the reasons why an overgrowth of Malassezia can lead to skin problems in dogs, such as itchiness, redness, and scaling.
Keep in mind that Malassezia is present on the skin of all dogs and is generally harmless when in balance with other skin microorganisms.
How Does Yeast (Malassezia) Grow?
Here’s a detailed explanation of how yeast (Malassezia) grows on a dog’s body:
- Attachment: The first step in the growth of yeast on a dog’s skin is attachment. Yeast cells adhere to the surface of the skin, hair follicles, or sebaceous glands. They can do this through specialized structures called adhesins, which allow them to recognize and bind to specific molecules on the host’s skin.
- Proliferation: Once attached, yeast cells begin to grow and multiply. They reproduce by a process called budding, where a small outgrowth forms on the parent cell and eventually separates to form a new yeast cell. The growth and proliferation of yeast cells on a dog’s skin are influenced by various factors such as humidity, temperature, and the availability of nutrients.
- Nutrient utilization: Yeast cells obtain nutrients from the dog’s skin, particularly lipids found in sebum (the oily substance produced by sebaceous glands). Malassezia species have a high affinity for lipids and can break down complex fatty acids to utilize them as an energy source. This lipid metabolism is essential for the growth and survival of Malassezia yeasts on the dog’s skin.
- Formation of biofilms (optional): In some cases, yeast cells may form biofilms on the dog’s skin. Biofilms are complex, three-dimensional structures formed by microorganisms that provide a protective environment for their growth. They consist of yeast cells embedded in a self-produced matrix of extracellular polymeric substances (EPS). The formation of biofilms can increase the yeast’s resistance to antifungal treatments and the host’s immune response.
Factors that can contribute to the overgrowth of yeast on a dog’s skin include:
- Excessive moisture: Warm and moist environments facilitate the growth of yeast. Skin folds, ear canals, and areas between the toes are particularly susceptible.
- Allergies: Allergic reactions can weaken the skin barrier and create an environment conducive to yeast growth.
- Weakened immune system: A compromised immune system due to stress, illness, or medications can make it difficult for the dog’s body to control yeast growth.
- Hormonal imbalances: Disorders like hypothyroidism or Cushing’s disease can disrupt the balance of the skin’s microorganisms, leading to yeast overgrowth.
- Antibiotics: Antibiotics can disrupt the normal balance of microorganisms on the skin, providing an opportunity for yeast to proliferate.
How Fast Does It Grow?
The growth rate of Malassezia can vary depending on the specific species, the nutrients available, and the environmental conditions. In general, Malassezia species can grow and reproduce relatively quickly, with some species doubling their population size in as little as a few hours under optimal conditions.
In laboratory settings, Malassezia species typically have a doubling time ranging from 3 to 8 hours when grown in a lipid-rich medium at the optimal temperature (around 30-37°C or 86-98.6°F). However, the growth rate on the skin may differ due to factors like the availability of nutrients, the presence of competing microorganisms, and the host’s immune response.
In the context of skin infections or overgrowth, it is not just the growth rate of Malassezia that is important, but also the interaction between the yeast and the host’s skin environment, immune system, and other factors that contribute to the development of skin conditions. The time it takes for a Malassezia-related skin condition to develop or worsen can vary widely depending on the individual dog, the specific circumstances, and the effectiveness of any treatments being used.
Various microorganisms coexist. These microorganisms compete with each other for resources, such as nutrients and space, and can also influence each other through the production of antimicrobial substances or by modulating the host’s immune response. Some common organisms that can compete with Malassezia on the skin include:
- Bacteria: The skin hosts a diverse community of bacteria, including Staphylococcus, Streptococcus, Corynebacterium, and Propionibacterium species, among others. These bacteria can compete with Malassezia for nutrients and adhesion sites on the skin surface. A healthy balance between bacteria and fungi, including Malassezia, is essential for maintaining skin health.
- Other fungi: Besides Malassezia, other fungi can be present on the skin, such as Candida, Aspergillus, and Penicillium species. These fungi can compete with Malassezia for resources, although the relative abundance of different fungal species can vary depending on factors like the skin’s microenvironment and the host’s immune status.
- Mites: Demodex mites are microscopic arachnids that live on the skin of mammals, including humans and dogs. They primarily inhabit hair follicles and sebaceous glands, feeding on sebum and cellular debris. Although they are generally harmless, their presence can influence the balance of other microorganisms on the skin, including Malassezia.
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What Can I Use To Address This Yeast?
If the dog has external presence of yeast then it’s time to address it topically.
Ketoconazole is an antifungal drug belonging to the azole class. It is effective against a range of fungi, including Malassezia, which is a genus of yeasts that naturally inhabit the skin of humans and animals. Ketoconazole works by targeting a crucial component of fungal cell membranes called ergosterol. Here is an overview of the pathway through which ketoconazole eliminates Malassezia:
- Inhibition of ergosterol synthesis: Ketoconazole inhibits the synthesis of ergosterol by targeting a specific enzyme called lanosterol 14α-demethylase (CYP51). This enzyme is involved in the conversion of lanosterol to ergosterol, which is an essential step in the biosynthesis of ergosterol in fungi.
- Disruption of fungal cell membranes: Ergosterol is a vital component of fungal cell membranes, providing structural integrity and regulating membrane fluidity. When the synthesis of ergosterol is inhibited by ketoconazole, the fungal cell membranes become compromised, leading to the accumulation of toxic intermediates and altered membrane permeability.
- Cellular damage and death: The disruption of fungal cell membranes ultimately results in cellular damage, leakage of intracellular components, and impaired cellular functions. As a consequence, the fungal cells, including Malassezia, are unable to maintain their normal metabolic processes and eventually die.
HOW CAN I TREAT MY DOG’S YEAST SKIN INFECTION AT HOME?
Ketoconazole is typically administered topically in the form of creams, shampoos, or lotions for treating Malassezia-related skin conditions. I first learned about Ketoconazole in 2018 when I first used it my dog Orbit.
In this article I write: “I found this spray on Amazon, paid for the expedited shipping and waited for it’s arrival.
It’s the PetMD Antiseptic and Antifungal Medicated Spray and its active ingredients have Chlorohexidine, Ketocconazole, and Essential Fatty Acids, Aloe and Vitamin E.
When the product arrived I immediately applied it quite liberally at full strength to Orbit’s affected areas. I sprayed her belly, her paws, and put some on a cotton pad and wiped her muzzle, her head and behind her ears with it.
10 minutes later she turned beet red. As in OMG what did I just do to my poor dog.
She didn’t look inflamed, or itch or look uncomfortable but her redness made me and others around her feel uncomfortable.
She stayed this red for 3 days.
APPLY THIS SPRAY WITH CAUTION
And I learned to dilute the product. I put some in a mug and the solution was probably 3 to 1. And the next time 4 to 1. And the time after that 5 to 1.
I continued to clean her very slightly – every other day.
By the next weekend she was yeast free.
I didn’t want to do the happy dance. After all we’d been at this for over a years and this was too good to be true.”
That said, not all dogs respond to ketoconazole because some Malassezia have become unresponsive to it.
What Else Targets Ergostol
I’m always on the hunt for alternative products.
Several antifungal agents can disrupt the function or synthesis of ergosterol in Malassezia pachydermatis and other fungi. These agents are commonly used to treat fungal infections, including those caused by Malassezia pachydermatis:
- Azole antifungals: Besides ketoconazole, other azole antifungals, such as fluconazole, itraconazole, and miconazole, inhibit the enzyme lanosterol 14α-demethylase (CYP51), preventing the synthesis of ergosterol and leading to the disruption of fungal cell membranes.
- Polyene antifungals: Antifungal agents like amphotericin B and nystatin belong to the polyene class of antifungals. These drugs directly bind to ergosterol in the fungal cell membrane, forming pores that increase membrane permeability and result in leakage of intracellular components, ultimately causing cell death.
- Allylamines and benzylamines: Antifungal agents like terbinafine and butenafine belong to the allylamine and benzylamine classes, respectively. These drugs inhibit the enzyme squalene epoxidase, which is involved in an earlier step of ergosterol synthesis. The inhibition leads to a depletion of ergosterol and an accumulation of squalene, causing toxicity and disruption of the fungal cell membrane.
- Thiocarbamates: Tolnaftate, a thiocarbamate antifungal, has a different mechanism of action. Although it doesn’t directly target ergosterol, it inhibits the enzyme squalene epoxidase, similar to allylamines and benzylamines, and affects ergosterol synthesis.
I don’t have any experience with the other antifungal agents and have stuck with shampoos and sprays that contain Ketoconazole.
Alternative treatments like green tea, witch hazel, MCT oil, pau d’arco, nettle, garlic, herbs, apple cider vinegar, and oregano oil have antifungal properties but do not directly inhibit ergosterol.
So How Does Yeast Grow From the Perspective of Chinese Medicine?
It all starts off in the gut. I ‘ve learned that visuals help so I created the graphic below to explain it. It’s fairly large – you can download it as it might be easier to read.
To get rid of yeast at the root level, we need to tackle it from the inside out.
First, also you need to know what foods to AVOID and never feed.
Avoid These Foods
- High histamine foods
- Green tripe
- Apple Cider Vinegar
- Fermented dairy
- Fermented vegetables
- Raw Goat’s milk
- Canned foods (canned sardines, mackerel, salmon, and pumpkin)
- Most Citric Fruits – kiwi, lemon, lime, pineapple, plums
- Shellfish (oysters, mussels, and clams)
- Dehydrated treats and chews
- Cold Food
Traditional Chinese Medicine (TCM) is an ancient system of medicine with a holistic approach to health and wellness. It focuses on maintaining balance within the body and harmony with the environment. In TCM, the body’s health is maintained through a balance of opposing forces called Yin and Yang, and the smooth flow of Qi (vital energy) and Blood.
From a TCM perspective, yeast infections in dogs, such as those caused by Malassezia or Candida, are often considered a result of an imbalance within the body. Some possible TCM explanations for yeast overgrowth in dogs include:
- Dampness: In TCM, Dampness is a pathogenic factor that can disrupt the body’s balance and lead to various health issues. Yeast infections are often associated with Dampness, as the fungi thrive in warm, moist environments. A dog’s constitution or living conditions may make it more prone to Dampness, leading to an increased risk of yeast overgrowth.
- Spleen Qi Deficiency: The Spleen, in TCM, is responsible for transforming food into Qi and Blood and transporting them throughout the body. A deficiency in Spleen Qi can result in a weakened immune system, making it difficult for the dog’s body to control yeast growth. Spleen Qi Deficiency can also lead to Dampness accumulation, further contributing to yeast overgrowth.
- Liver Qi Stagnation: The Liver, in TCM, is responsible for the smooth flow of Qi throughout the body. Liver Qi Stagnation can lead to an imbalance in the body’s energy flow and contribute to the development of yeast infections. Stress, emotional factors, or environmental factors can contribute to Liver Qi Stagnation in dogs.
- Heat and Toxicity: From a TCM perspective, yeast infections can also be related to an accumulation of Heat and Toxicity within the body. This can result from an imbalanced diet, environmental factors, or other underlying health issues. Excess Heat and Toxicity can create a favorable environment for yeast growth and contribute to inflammation and skin irritation.
TCM treatment for yeast infections in dogs focuses on restoring balance within the body and addressing the root cause of the problem. This can include:
- Herbal remedies: TCM practitioners may prescribe herbal formulas to help clear Dampness, strengthen the Spleen, soothe the Liver, and eliminate Heat and Toxicity. These formulas can be administered orally or applied topically, depending on the dog’s condition.
- Acupuncture: Acupuncture involves the insertion of fine needles at specific points on the body to help restore the flow of Qi and Blood, alleviate pain, and promote healing. Acupuncture can be used to help strengthen the immune system and improve the overall health of the dog.
- Diet modification: TCM practitioners may recommend dietary changes to help restore balance within the body and support the dog’s immune system. This can include feeding the dog a balanced diet that is appropriate for its constitution, as well as incorporating specific foods or herbs with cooling or dampness-clearing properties. In my Heal The Gut Package I guide dog parents to eliminate yeast through food.
- Lifestyle changes: Ensuring a clean and dry living environment, providing regular grooming, and reducing stress can help prevent yeast overgrowth in dogs from a TCM perspective.
Best Diet For Yeasty Dogs
Feeding your dog a fresh, whole-food diet can significantly improve their health, particularly for dogs suffering from yeast overgrowth. Kibble, which is a highly processed pet food, often contains high levels of carbohydrates, fillers, and artificial additives that can contribute to a damp environment internally and then a yeast overgrowth and make recovery more difficult. In contrast, a fresh food diet provides essential nutrients, promotes a healthier gut microbiome, and supports the immune system, all of which can help keep yeast overgrowth in check.
For dogs with a strong digestive fire, a raw food diet may be a suitable option as it closely mimics their natural, ancestral diet. However, it is important to consider that raw food can have higher histamine levels, which might exacerbate yeast overgrowth or trigger allergies in some dogs. In these cases, feeding cooked fresh food is often the better choice, as cooking can reduce histamine levels while still providing the vital nutrients required for optimal health.
By offering a balanced, species-appropriate fresh food diet tailored to your dog’s individual needs, you can support their overall well-being and help prevent and manage yeast overgrowth more effectively than with processed kibble.
Consider The Constitution Of The Dog
In Traditional Chinese Medicine (TCM), the individual constitution plays a vital role in understanding and treating various health conditions, including Malassezia overgrowth. The constitution, also known as “ti zhi” in Chinese, refers to the unique physical, emotional, and energetic characteristics of a person or animal. Each individual’s constitution is influenced by factors such as genetics, prenatal and postnatal environment, lifestyle, and diet.
I was explaining this to a client and I switched off dogs and talked about how this might apply to people.
When my beloved and I traveled down to Tulum he broke out on his back. He had told me that the Minnesota summers were too harsh for his skin and I never realized it until I witnessed how much havoc it caused to his skin.
I on the other hand, who grew up on a tropical island, was loving the weather. My constitution does well in hot weather.
On the flip side, when we went on vacation to Europe many years ago during the late fall, it was so cold my face hurt. He on the other hand enjoyed the weather tremendously.
When one is looking at their dog, they must take into account the location, climate, and constitution as well.
By considering the individual constitution, TCM offers a personalized, holistic approach to health and well-being. This allows for tailored treatments that address the root cause of Malassezia overgrowth and other health issues, rather than merely focusing on alleviating symptoms.
Malassezia is a naturally occurring single-celled yeast found on the skin of all dogs. When present in normal amounts, it is harmless and even beneficial. However, when growth conditions are favorable, Malassezia can proliferate and cause skin infections and discomfort. Factors such as diet, allergies, and underlying medical conditions can contribute to Malassezia overgrowth.
Antifungal medications, such as ketoconazole, target ergosterol in the fungal cell membrane to eliminate Malassezia. Alternative treatments like green tea, witch hazel, MCT oil, pau d’arco, nettle, garlic, herbs, apple cider vinegar, and oregano oil have antifungal properties but do not directly inhibit ergosterol. Probiotics can help support a healthy gut microbiome and prevent the overgrowth of Malassezia and other harmful organisms.
From a TCM perspective, the key to preventing and treating Malassezia overgrowth lies in addressing internal and external imbalances through dietary adjustments, herbal remedies, and other holistic treatments. Ensuring a balanced, species-appropriate diet, proper grooming, and maintaining a healthy environment can help prevent Malassezia overgrowth and maintain your dog’s overall health and well-being.
As always, thank you for stopping by and I wish you and your dogs, good Health!
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Hannah Zulueta obtained her Certificate in Canine Nutrition from CASI Institute. She is also studying for her Doctorate in Acupuncture, Traditional Chinese Medicine, and Herbalism from the esteemed Pacific College of Health and Medicine.
She resides in San Diego with her three dogs, Maggie, Orbit, and Mr. Higgins.