Yeast Overgrowth in Dogs – What Can You Do?

Yeast is a natural part of your dog’s microbiome. Problems arise when the environment on the skin, in the ears, or on mucous membranes changes in a way that allows yeast to multiply excessively. In dogs, Malassezia pachydermatis is the most common yeast associated with skin and ear problems. It normally lives on the skin but can grow rapidly when conditions allow it.

Typical Signs of Yeast Overgrowth

Yeast overgrowth on the skin and in the ears can cause fairly characteristic signs: strong, sweet, or “yeasty” odor greasy or oily skin and coat red and irritated skin excessive licking and chewing of the paws recurring ear problems with waxy/brown discharge dandruff and crusting darker and thickened skin in chronic cases intense itching Yeast can be detected through cytology, where a veterinarian takes a sample from the skin or ear and examines it under a microscope. Candida is also a type of yeast. Candida albicans can naturally be found in places such as the gastrointestinal tract, but clinical candidiasis is much less common in dogs than Malassezia-related skin and ear problems. Candida can become a problem when the balance in the gut is disrupted, for example after antibiotics. This can allow the yeast to grow more than it should.

Cause – Why Do Dogs Develop Yeast Overgrowth?

Yeast overgrowth is often secondary to another problem. Allergic/atopic skin disease is one of the most common underlying causes of Malassezia overgrowth in dogs. This is why it is important to address more than just the yeast if the problem keeps returning. In her book The Herbal Dog, Rita Hogan places strong emphasis on the connection between gut flora, antibiotic use, and yeast overgrowth. She describes how antibiotics can reduce beneficial bacteria in the gut and make it easier for yeast, Candida, and other opportunistic microorganisms to grow, which may in turn be associated with symptoms such as sensitive digestion, food reactions, and itching.

What Should You Do?

**1. Olive Leaf Extract** One interesting plant extract for yeast overgrowth is olive leaf (Olea europaea). One of its most important active compounds is the polyphenol oleuropein. At the DogRisk Seminar in September 2025, veterinarian Dr. Matthew Muir discussed Olive Leaf Extract in his lecture Phytotherapy as Functional Medicine. He placed olive leaf extract among “Biofilm Degraders” and described it as an antimicrobial intervention that should be used in a targeted way, at lower doses, and for shorter periods of time. It was also specifically mentioned in relation to atopy. Rita Hogan also describes olive leaf as an antimicrobial herb and highlights its oleuropein content for targeted use against yeast and biofilm. There is also an interesting mechanistic explanation. Laboratory studies on Candida albicans show that oleuropein has antifungal activity and can affect several of the properties Candida needs in order to establish itself. Oleuropein has, among other things, reduced adhesion – the ability to attach – and filamentation, both of which are relevant to biofilm formation.

What is biofilm?

Biofilm is a protective layer that yeast and bacteria can build around themselves after attaching to mucous membranes in the body. This layer can make them more difficult to affect and may be an important reason why an overgrowth keeps returning. This is why it can be relevant to address both the yeast itself and the biofilm protecting it.

**2. Look at the diet** Diet should also be considered when a dog has recurring yeast overgrowth. Yeast lives and multiplies on sugar. During a yeast flare-up, dietary changes are essential if supplements such as olive leaf extract are going to have an effect. Fast-digesting carbohydrates such as starch, sugar, grains, potatoes, rice, and pea starch in kibble are broken down into glucose in the dog’s body. Glucose is yeast’s primary source of fuel. By reducing carbohydrates in the dog’s diet, you can “starve” the yeast from the inside. A simple, fresh, meat-based diet, such as raw feeding or a homemade BARF diet, is one of the most effective ways to eliminate the carbohydrates that yeast feeds on. By removing starch, you are no longer feeding the overgrowth, giving the immune system and gut a better opportunity to restore their natural balance.

**3. Rebuild the gut Microbiome** If the problem developed after antibiotic treatment or alongside obvious dysbiosis, the strategy should not focus only on reducing yeast. The microbiome also needs the opportunity to stabilize again. In her protocols, Hogan recommends the probiotic yeast Saccharomyces boulardii because it actively combats harmful yeast without causing overgrowth itself.

Note: “Die-off” (Herxheimer reaction):

When the yeast is “starved” and begins to die, symptoms such as itching may temporarily worsen for a couple of days before the skin and digestive system noticeably improve.

**4. Detoxification and Binding** When yeast dies (especially during Phase 2), endotoxins are released, which can cause temporary itching or discomfort (Herxheimer reaction/die-off). Moor Mud, which acts as a natural binder (sorbent) as the humic acids in the mud bind to the yeast's waste products in the gut, carrying them safely out through the stool while simultaneously protecting the intestinal mucosa.

# Yeast Overgrowth Protocol **Phase 1: Dietary Change** - **Action & Content:** Transition to a fresh, meat-based diet (e.g., raw food/BARF). - **Purpose & Notes:** Eliminate glucose from fast carbohydrates and starches to starve the yeast of its primary nutrient source. **Phase 2: Antifungal Phase** - **Action & Content:** Olive Leaf Extract (oleuropein). Duration: 3–4 weeks. - **Dosage:** Gradually increase dosage over 3–5 days (see store for specific dosing). - **Purpose & Notes:** Actively weaken yeast cell walls and reduce overgrowth in the digestive tract. **Phase 3: Rebuilding & Gut Support** - **Action & Content:** *Saccharomyces boulardii* (non-colonizing probiotic yeast) and Bovine Colostrum. - **S. boulardii Purpose:** Outcompetes harmful yeast/bacteria and supports the intestinal mucosa. - **Colostrum Purpose:** Supports the gut barrier and immune system. *Note: Hogan recommends this as an alternative if S. boulardii is not tolerated. In studies, it increased fecal IgA as well as microbiota stability and diversity.* **Phase 4: Detoxification** - **Action & Content:** Moor Mud. - **Purpose & Notes:** Binds endotoxins released during yeast die-off (*Herxheimer reaction*)…