I arrived late in the day. It was almost feeding time and the horses were inside. As I walked through the open barn door I smelled it, the unmistakable stench of thrush. Studies claim over 90% of domestic horses have an active infection in their feet. That may seem high but at least 90% of horses I encounter have some form of thrush – some mild, some severe – and the smell in this barn agreed with statistics.

Thrush is at epidemic proportions in our horses and no one seems to notice! It’s so common it’s not recognized, or perhaps is accepted as normal.  Every barn has bottles of chemical treatments on hand for their never ending battle of thrush.   More importantly, every barn has horses who exhibit heel pain stances, who are ‘tender’ footed or ‘small’ footed.  Every barn has lame horses.  One common reason is the ever popular presence of Thrush!  

Does your horse have thrush?

Quite possibly the answer is ‘Yes’. Thrush is a very common anaerobic bacterium found in the soil and is everywhere horses are kept. It thrives in damp environments like stall floors, over crowded or ill-designed outdoor pens, run in sheds and loafing areas. The land becomes saturated with high concentrations of urine and manure. As this decays, thrush grows like mold in a Petri dish. Add the other epidemic of improper foot form and high sugar feeds to the equation and you create the perfect environment in hooves for thrush to live and feed

How do you know it’s thrush?

Thrush does not always have a textbook presentation of black oozing ‘goo’ with a super bad smell. While this is an advanced form (trench foot) there are moderate forms (athletes foot) that can wreak havoc on hoof health and negatively affect the body and behavior as a whole.

In early stages it begins with flaky sole with shiny black areas along the wall sole connection.  Thrush can affect the frog in the collateral grooves and/or central sulcus, the bulbs, the white line and even the sole.   It’s similar to foot rot in cattle or sheep. It is not uncommon in many cases for secondary infections like ‘greased heels’ and ‘rain rot’ to be present.

• What do you see? When cleaning and inspecting your horse’s feet, is the foot the picture of health with a clean distinction between parts: wide, thick, calloused uniform frogs that blend into wide, smooth heel bulbs – smooth, shiny soles – clear white line connections? Or maybe you see some warning signs of a foot susceptible to thrush: chalky, flakey sole – tattered, black frog- deep crevices that trap manure and bedding?
• NOTE:  You should be able to press…with ALL your might with the pointy side of the hoof pick INTO your horses frog with very little give.  Most horses you would poke right into the frog like this.

• What do you feel? Does the foot clean easily almost as if it’s self cleaning? Is the sole  hard and shiny or chalky and sticky?    Is there soft black material in  deep cracks and grooves? When you press on the frog is it strong and super firm like a rubber stall-mat or is it weak and gives easily to pressure like raw meat?

What do you smell? Naturally kept and trimmed hooves simply don’t smell or perhaps have a mild odor of fresh manure or damp clean earth. Does your hoof pick come away smelling foul - like an overused chemical toilet at the country fair? That’s ‘trench foot’ thrush. Common, but not normal.

What can you do?

The first thing is to recognize that thrush is a symptom! It is not something that a horse can ‘catch’ or come up with in one day.  There are factors predisposing your horse to thrush.    A horse presenting thrush is in chronic stress with a compromised immune system from one or more of the following:

• The shape of the foot itself. The trim has a lot to do with whether or not a horse is likely to get deep seated thrush or an easily rectified temporary or seasonal condition.  Overgrown or conventionally trimmed and shod feet are more likely to develop thrush due to the unnatural hoof shape and poor circulation. A good barefoot trim creates a self cleaning foot and promotes blood flow and function which helps eradicate thrush.

• A high sugar or concentrate diet encourages the growth of thrush – like acne of the foot. Too many horses are over-supplemented with processed feeds/grains and other ‘additives’. Feeding a staple diet of free choice grass hays improves health and strengthens the immune system.

• Lack of movement. Stalled horses or horses in small turnouts are at a much higher risk. Urine is very concentrated, more so if the horse is fed grain/ concentrates. Bedding soaks up the caustic urine and returns it to the foot.  This shows up in the sole as an orange or cantaloupe color. I call this urine burn, and it is usually accompanied by black, ragged, narrow frogs, dull, flat bulbs and a foul smell. Enhanced natural movement with a correct barefoot trim ensures better circulation, and with attention to footing and feeds, thrush will  be a thing of the past.

 The simple thing is thrush can not exist in a healthy functioning foot!  No matter how wet it is outside. Natural horses handle the wet seasons with their built-in protection of a strong immune system.   And their healthy shiny feet have a thin shellac-like coating which helps the foot self clean and maintain proper moisture balance.

To speed-treat thrush you can what I call the ‘magic spray’: active apple cider vinegar in a spray bottle with about 5 -10 drops of tea tree oil. Clean the feet well with a hoof pick and a steel brush. Remove any large tattered edges on the frog. Spray 2 to 3 times a day for at least 6 weeks. Make sure you get in the central sulcus of the frog as well as the collateral grooves. As a preventative measure, spray the foot daily.   

Be sure your treatment includes a proper barefoot trim and plenty of exercise to increase circulation and strengthen immunity.  And remember, chronic thrush is much less likely to occur in grass fed horses.

The ultimate goal is to prevent thrush. By treating now and taking new management approaches, you may never see thrush again.

For more information on enhancing lifestyle, diet and trimming, visit www.equinextion.com.

Prevention is the key!!

About Lisa Huhn and Anne Louise MacDonald

Lisa has 6 years of Post secondary education in Animal and Equine Sciences and Pre-Veterinary Studies.

With over 10 years of additional study and research Lisa developed, tested and implemented the protocols for the Equinextion therapeutic performance trim.

Lisa has extensive experience in A-listed western riding, roping, racing, hunter/jumper-showing, training, coaching and judging before concentrating on classical dressage.  She developed and hosts the website www.equinextion.com and the #1 online bulletin board on barefoot trimming and natural horse care.

Lisa continues to give lectures to veterinary colleges and other equine organizations and schools across North America.  She offers clinics and lectures on trimming and natural horse management and small acreage design. 

Equinextion also offers trimming courses and a new certification trimming course for those wanting to trim professionally. 

Anne Louise MacDonald is the author of 5 books and has worked with equinextion since 2004.