Is Your Dog A Yeasty Beast?

Another particularly common issue we see here at My Pet Nutritionist is yeast! More technically known as candida, it is actually harmless when kept in check. The issue is when our dog’s system goes a little awry and can’t keep those little blighters from colonising.

Whilst it sounds like a military operation, the dog’s system functions very much like that. Let’s take a look at yeast in a little more detail and how we can armour dog’s defences for a fighting chance!

What is Yeast?

Candida is an opportunistic fungal pathogen. It is a normal part of the gastrointestinal flora and genital tracts. Healthy systems are more than capable of keeping it in check with their beneficial bacteria. The issue arises when there aren’t enough good guys to keep the bad guys in check.

The good bugs we find in our dog’s gastrointestinal tract will compete with the bad bugs for food sources and attachment sites.

As we know there are a number of factors that can skew the microbial community found in our dog’s system.


Broad spectrum antibiotics target all bugs,so whilst they get rid of the ones running amok, they also wipe out the beneficial ones too. Whilst the microbiome can recover to some extent, eventually; this takes time and there’s evidence which suggests key species are never fully repopulated.

Findings here


There are clear links that stress, whether physical or emotional, affects the composition of the gut. On many occasions, stressor infliction significantly reduces the good guys. This has been associated with increased inflammation in the gut, which then continues the cycle.

Findings here

The Environment

There is a huge amount of data which shows exposure to environmental pollutants significantly alters the gut microbiome. This includes bisphenols, phthalates, organic pollutants, heavy metals and pesticides.

Bisphenol is an industrial chemical used to make hard, clear plastic. It is also found in epoxy resins which is often used as a protective later in some metal food and beverage cans/tins. Bisphenol has been linked to reduced microbiome diversity, and a significant decrease in protective bacteria.

Phthalates are plasticisers and stabilisers found in vinyl flooring, clothing, detergents, personal care products, toys, medical equipment, and plastic packaging. Because they are non covalently bound to materials, they can leach into the environment. Phthalate exposure induces microbiota changes and has been known to inhibit the synthesis of certain short-chain-fatty acids.

Heavy metals are associated with reduced microbiota diversity along with the altered metabolism of vitamin E and bile acid.

Findings here

Pesticides are renowned for altering the gut microbiome. This not only includes the pesticides administered to pets (flea and tick treatments), but also those found in the environment, particularly those sprayed on public footpaths. What is also worth considering is that antibiotic use has been seen to increase bioavailability of pesticides within the body.

Findings here

You are what eat!

Of course, nutrition also plays a part in modulating the gut microbiome. But we always knew that.

We are all pretty selfish in evolutionary terms, and this includes the bugs we find throughout our body. Our ultimate aim, and theirs, is to survive. So, we just need to modify how many of them actually do. This means keeping the colonies of good bacteria strong, so offering our dogs a diet full of pre and probiotic foods! Prebiotics are like the fertilisers in the garden, they help to feed and grow the beneficial bacteria in our garden. Probiotics however contain live organisms which can contribute to the population of the garden.

Findings here

There are a number of prebiotic foods suitable for dogs and they include mushrooms, chicory root, garlic and dandelion greens. Probiotics include fermented food, but supplements are available; soil-based are a good call for your canine friend (hold off on the fermented food until later, if your dog has already developed an overgrowth).

Yeasts seem to like sugar as fuel, so diets high in grains, starches and other carbohydrates seem to contribute to an overgrowth. Generally, certain beneficial bacteria will metabolise these sugars, keeping candida in check by disrupting its food supply, but in the absence of good bacteria, candida is partying it down at the all-you-can-eat buffet!


A weakened immune system is also a huge risk factor for developing a candida overgrowth. Whether this has been a natural progression over a period of time for a range of factors, or even due to medications like steroids.

Immune function has natural peaks and troughs, young dogs and ageing dogs naturally have a lower function, but pre-existing conditions along with a range of medications can affect it too.

The immune system is like a nosey neighbour. It keeps tabs on everything going on in the body and knows when something isn’t quite right. When it identifies something as non-self, it sends the army to fight the foreign invader and, all being well, wins, before sitting back down with its cup of tea. The issue arises when it can’t get up from its chair and so the foreign bodies are left to invade.

There are a number of factors which can compromise immune function from sleep, to stress and nutritional status; there are several key nutrients essential to its performance.  So, supporting this is essential in the prevention and treatment of any bacterial overgrowth.

Top Tips:
  • Adequate rest
  • Reduced exposure to stress
  • Nutrient dense diet withVitamins A, C, D and B’s, along with Zinc, Selenium, and Iron
  • Address any pre-existing issues like inflammation in the digestive system or poor pancreas function which can contribute to poor nutritional status Findings here
  • Careful use of medications like antibiotics, NSAIDs and steroids

Findings here on Vitamin D

Findings here on Zinc

What if your dog has already got an overgrowth?

If indeed your dog has developed a candida overgrowth, you will notice symptoms like:

  • Ear infections
  • Greasy coat
  • Sores
  • Odour (yes, that cheesy type of smell)
  • Green/yellow discharge
  • Crusty/flaky skin
  • Hair loss
  • Itching/scratching
  • Incessant licking/grooming of an area due to irritation
  • Rust like colour around the genitals or toes
  • Gut issues
  • Seasonal allergies

And there are some things that can start you off on the right foot in tackling it.

Firstly, as we have mentioned, glucose concentration is directly related to candida growth, so removal of those high starch foods is key (no dry food for you). This is why we always advocate an unprocessed, fresh food diet.

Pin pointing food intolerances and working on gut lining and integrity will ensure a healthy produced mucin that supports response to food antigens. if you dog is reacting to foods, this will create more inflammation that will disturb the bacterial balance, gut function and fuel candida overgrowth.

There is also an interesting school of thought that yeast has an affinity for heavy metals, which is great; heavy metals have been removed from contaminated soil with the use of yeast!  But because of this affinity, yeast can grow,well, so if there is a high level of heavy metal contamination in the dog,yeast will thrive. Heavy metals as we know kill off the beneficial bacteria, so there aren’t even any good guys to help us out!

Findings here

Avoid contamination where possible; particularly if you feed fish and try to source organic food; pesticides and herbicides sadly have a high contamination rate. Opt for filtered water if possible, too!

Findings here

Whilst an off-kilter microbiome can fuel candida overgrowth, it pays to be careful in how you repopulate it. In the presence of an overgrowth, it is easy to consider that repopulating the good guys will help fight the bad guys. The issue with fermented foods which are full of great guys, is that fermentation occurs when carbohydrates are broken down by bacteria, yeasts or other microorganisms. So, there is a chance that the prebiotics found in the fermented foods can feed the yeast in the dog too, so beware!

Working with antimicrobial/antifungal functional ingredients such as garlic (yes it is safe if given correctly and if the sulphur component is tolerated), oregano, barberry, thyme, pau d’arco, and rosemary (caution taken in epilepsy), can be incredibly helpful is managing a fungal overgrowth.

Often, anti-fungal shampoos are prescribed to manage yeast overgrowth on the skin; this raises another point. As we know, the skin also has a community of microbes; not only does the anti-fungal wipe out the bad guys, but it takes the good guys too. Then, once the dog is bathed, they are often encouraged to sit by the radiator to dry off (sometimes even in a drying robe). Microbes all have their perfect environment; warm and moist ones can populate many(including the bad guys). Even if you’re not treating with a shampoo, this is worth considering for those water-loving dogs who can’t seem to shake recurring infections.


Yeast can be a complex issue to manage. It is actually harmless when kept in balance, but issues occur when the gut or skin gets into a state of dysbiosis (overwhelming bad bacteria). A weakened immune system doesn’t help, along with the use of many medications like antibiotics, flea and tick treatments, steroids and NSAIDs. Prevention should consider supporting a healthy immune system and microbiome, but treatment and management can be a touch trickier.

We would always advocate:

  • Feeding a fresh, unprocessed diet – avoiding high sugar foods and sometimes avoiding any veg at all for the time being
  • Offer filtered water
  • Avoid contamination (if you feed fish, and buy organic if possible)
  • Use prebiotic and probiotic foods to support gut health (when appropriate)
  • Heal the gut lining and look into natural anti-fungal agents if there are stubborn overgrowths
  • Maintain optimal skin health

Here at My Pet Nutritionist, we offer consultations for those dogs suffering with yeast overgrowth; let us help you put a plan together by booking a consultation here. We consider all aspects of health and why this may be a problem in the first instance.

Thanks for reading!

MPN Team x

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