Thrush and More

My last article I wrote was on "Thrush, White Line Disease and more ..."

In the article, I discussed, briefly, how yeast can invade horses' hooves making them lame.

Yeast infections - the mystery lameness

Yeast infections are the "more" of this article, and I see more of it than I'd certainly like to see and mostly it goes undiagnosed and untreated. What can happen is that the "mystery" lameness perpetuates and has even ended in premature euthanasia of the horse. 

Allow me to briefly recap what a yeast infection is from my former article.

When hooves are not balanced correctly the heels can become contracted forming a crevice between the heel bulbs. Yeast, being an opportunistic organism, will seek out damp, warm places to invade, just as thrush bacteria does, so those cracks between the heel bulbs provides the perfect hiding place for yeast.

So what is "yeast" and how is it contracted?

"Candidiasis" is a localized mucocutaneous disease caused by species of the yeast-like fungus Candida, most commonly C albicans. It is distributed worldwide in a variety of animals. ... However, Candida spp have been considered a cause of arthritis in horses and mastitis and abortion in cattle." -- MERCK VET MANUAL

"Yeast" is Candidiasis, proliferation of C albicans. Any woman who has suffered from Candida knows the pain and the discomfort that accompanies the condition. The same C albicans that causes the yeast infection for women is the same C albicans that can cause discomfort and even severe lameness and more in horses. 

Candida can affect horses of all ages, breeds and types. It is not picky. All it needs is soft tissues that is warm, moist and a host that is immune deficient. 

The worst that can happen

An extreme but well documented case of yeast infection is noted in . 2013 Feb; 54(2): 176–178.  --

"A 2-year-old gelding was referred for evaluation of severe right forelimb lameness. The horse was grade 4/5 lame on the right forelimb. Clinical, laboratory, and radiographic findings were consistent with septic arthritis and osteomyelitis. Due to poor prognosis the owner elected euthanasia. Histopathology confirmed chronic arthritis and osteomyelitis with intralesional yeast (Candida species)."

Upon postmortem examination the colt was found to have Candida Osteomyelitis. Candida was found in the BONES of the colt.

The port of entry to the bone by the yeast is often difficult to establish but, based on the clinical history, many authors propose that it is by wound contamination, traumatic implantation, or arthroscopy. "Wound contamination" is contamination due to diseased soft tissue of the hoof and foot (the tissues inside the hoof capsule). It is also known that Candida species can invade bones or joints by blood circulation.

It has also been noted that candiasis can also take hold in an immune-deficient host. That is, any horse with a compromised immune system. 

What causes deficient immune systems?

The answer to that question is simple - being alive!

Toxins, pesticides, herbicides, processed feed, vaccines, antibiotics, chemical supplements, negative stress, illnesses, emotional stress  . . . . .  In the world we live in now we are all pretty much immune deficient.

I've mentioned in former articles that we must think in terms of "feeding the immune system" vs feeding the horse. In doing so we are also "feeding the hooves". What goes INTO the horse grows OUT through the hooves. Always. So this is  Number 1 in battling a yeast infection in the hooves of a horse.

Number 2 is to make sure that if the horse is struggling with Thrush, that he is treated with topical anti-fungal as well as treated systemically with anti fungal food/medicine.  In doing so we are treating the blood which is a carrier of C albicans.

Number 3 is paramount as well to the complete healing of the horse and its hooves - detoxing the horse. One can treat the immediate situations of thrush and yeast but if one does not treat the ROOT CAUSE then all is for nothing. But, when treating for Thrush one MUST also treat for yeast ... yeast THRIVES on dead bacteria. Thrush is a BACTERIA, not a fungus.  It also thrives on sugars. Simple sugars. Sugar and iodine may kill off bacteria but it feeds yeast.

What to do if you have a horse that is not responding to thrush treatment

So if you have a horse that is just not responding to thrush treatment consider that it may also be battling C albicans. As described in my former article, yeast will hide in that crevice that is so often seen between the heel bulbs. When cleaned out with a pick the crevice area is not only sore but also may also exudes a white, cheesy-like material that smells like cheese. Unlike the odor of thrush, that foul, nauseating black tarry substance in the collateral grooves and frog, the odor of C albicans is not overpowering and actually can be rather faint and puzzling. 

Thrush and Yeast CAN invade the bones if not treated correctly

This is where we find that, even though the thrush is treated and has been eradicated, the horse is still lame with a 'mystery lameness'. Fungal osteomyelitis and arthritis caused from C albicans can be resolved with appropriate treatment. The outcome of the treatment will depend on the individual horse and if it is immunocompromised or not.

Yeast infections are a WHOLE HORSE disease and must be treated as such

Topical treatments are often not enough to ensure complete recovery. Although clinical diagnosis of fungal osteomyelitis (yeast in the bone of the hoof) is difficult, blood culture diagnosis is simple because yeast can be easily identified microscopically.


 Gwenyth Browning Jones Santagate is the world-renowned author of "10 Secrets to Healthy Hooves" and "Natural Hoof Anthology" as well as a noted author for various international equine publications including The Horses Hoof, Equine Wellness, Natural Horse Planet as well as a contributing author for the 2001 United States Federal Mounted Border Patrol Training Manual. For the last 37+ years, she has maintained healthy hooves with natural trimming on thousands of horses and specialized in pathological rehabilitation hoof care for the last 18 years. She and her husband John keep a small herd of their own equine in NE Connecticut and continue to offer consults for horses in need. For further information please click here:


Gwenyth is available for freelance assignments, contract work and consulting.




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