Thrush is something that at one time or another all horse owners will likely have to deal with. It is not a product of neglectful horse care, nor is it a product of unsanitary living environment etc. Thrush is a combination of bacteria and fungus that can eat away at the frog tissue in the hoof. These bacteria and fungus are more prominent in wet conditions and thrive in moist ground, but can also be a problem in dry conditions. In the image above you will see the healthy frog on the right, the thrush infected frog on the left. You will notice that the central sulcus, the area at the rear of the frog in the middle, in the healthy hoof is just a small indent, but in the affected hoof it is a deep crack. This is the first area that thrush usually starts to affect. What happens is the the thrush eats away at the healthy tissue and creates a "home" for itself withing the sulcus of the frog. The deeper the crack, the better the hiding spot for the thrush to thrive and eat more healthy tissue. It is a vicious cycle and can be extremely hard to beat once it gets to this advanced stage.
Minor surface thrush is much easier to deal with. Some ratty tags on the frog, or a small infection of the central sulcus can usually be treated with diligent hoof picking and 2-3 times a week topical treatments. More severe thrush can take weeks or even months to clear up and can require soaking, topical treatments, booting and even diet/nutrition changes.
So why is thrush an issue? At the start with a minor case, thrush doesn't really alter the horse in any way. If we catch it early enough and treat it then it is a non issue. If thrush persists and manages to eat into the frog tissue deeper it can cause the horse to feel some sensitivity when loading the back of their hoof and can cause them to land flat or toe first as opposed to heel first as they are intended to land. Horses land heel first in order to use the frog and its underlying structure, the digital cushion, to absorb impact and dissipate energy vibrations. When the horse alters its movement and doesn't land heel first that impact energy travels up the leg into the joints, shoulders/hip and back and causes excess strain on the body. This can create a cascade effect that can significantly affect the performance of the horse and in serious cases can even lead to lameness.
When the thrush eats through the frog and into the sensitive digital cushion it is extremely painful for the horse. The hoof and its outside structures are designed to protect, and are insensitive structures, meaning they do not have nerves and blood supply directly within them. The nerve receptors and blood supply are located within the sensitive structures: the digital cushion, solar corium and lamina. So this means that a minor surface infection of the frog really won't cause much pain, however once the thrush eats into the digital cushion it is in fact an open wound of the horse, and is painful when impacting the ground. The horse then alters their movement to avoid loading the frog as much as possible. This is an issue because of the previously mentioned strain on the body, but also because healthy frog tissue is generated because of positive impact forces, and without the horse loading the frog it won't receive these forces. This creates a long term problem as the frog and digital cushion will atrophy over time due to lack of stimulation and will alter the shape of the hoof capsule. You then have a significant reduction of impact energy dissipation and a horse that is absorbing that impact in their joints, therefore more prone to develop arthritis and other joint related conditions.
The pictures below show you the severity of a thrush infection once it gets into the digital cushion. These cadavers have the outside structures removed and the one on the left has an infection so deep that a hoof pick can be inserted into the crack approx 1/2 an inch. This is a deep open wound for the horse and extremely painful. The cadaver on the right shows a healthy digital cushion with a normal central sulcus without infection.
So what can we do about it? For minor infections treating topically is easy. Your local tack store will have several products available that are designed to kill the harmful bacteria and fungus that cause thrush. My personal word of of caution would be to read the ingredients label on those products. What you want is something that will kill the harmful bacteria and fungus, but not the healthy tissue. A lot of commercially made thrush products have ingredients like formaldehyde, formalin, turpentine etc. These substances are toxic to healthy tissues and will indeed kill the thrush but also the regenerating frog tissue. My favorite for minor surface thrush are tea tree ointments, gentian violet treatments or zinc oxide cream marketed as diaper cream for babies.
Think about a deep thrush infection like an open wound on your own skin. Use products that will keep it clean but also encourage healthy growth. Products such as antibacterial wound scrubs used in human medicine, as well as barrier creams and ointments. My personal method for treating for this type of infection is as follows:
Easyboot Cloud therapy boots are also a great rehab boot. I sometimes use these if I need more protection for the hoof and a thicker padding. These are not suitable for riding so it makes them strictly a turnout/therapy boot. If you are looking for Cloud boots contact me as I can special order them.
When it comes to rehabilitating horses, or for me even just owning horses, I approach it with the whole horse in mind. For me my horses are companion animals, riding animals, and animals that I use to facilitate my business. They are also living, breathing beings with their own thoughts, feelings and needs. They make friends, have family groups and form attachments to certain horses, animals and people. My main area of focus in my business is hoof care, but in order to achieve optimal hoof health there are many other areas that must be working properly in order for the hooves to be healthy.
Let’s start with the diet. There are many conflicting opinions on the optimal diet for our horses. I have taken several equine nutrition courses, been to many seminars and done plenty of research. What I have found is that individual horses needs vary so a one size fits all approach doesn’t work. This post isn’t about nutrition specifically so I will try to keep it short. Up until recently I had a specific combination of feeds and minerals that I fed my herd of 10 on a daily basis. I was feeding each feed or mineral for a specific reason that I had predetermined that the horses needed. I was feeding those minerals because of what I had learned about minerals and hoof health. How did I come up with the theory that they needed them? Well I had read, researched or had been told by a trusted source that they needed them. I had never seen any reason in my horses’ outward appearance, behaviour or apparent health that made me think there was a deficiency, but I assumed like most people do that they should be supplemented with something and therefore I built my list of supplements and off I went to the feed store. I fed these things for years until just this past spring when I heard something that interrupted my thought pattern. I had scheduled an osteopathic treatment for two of my horses with Dr. Laura Taylor and it was while in deep discussion with her about equine diets and nutrition that she said something that has stuck with me ever since. She said “if you are feeding or supplementing your horse with something, you should see some type of result”. Weather those results are physical, such as seeing an improvement in their hair coat or outward appearance, emotional, such as seeing less anxiety or behavioural problems, or internal, such as something affecting the organ systems in the body or the musculoskeletal system causing stiffness or even lameness. The point is you should see some type of result from what you are feeding, or you should see a result of not feeding it... This caused me to rethink my horses diets and cut out everything but pasture and hay for three months. What I found was that there was no change in them. Their hair coats were still beautiful and shiny, their hooves were still brilliant and they were still emotionally sound and happy. The moral of the story for me was to keep it simple. And I’m not saying all horses don’t need supplements, but what horse owners need to do is understand what they are feeding and to make sure it is necessary for your horse before blindly feeding something just because someone else does, someone told you to, or because of some fancy packaging. I have now started to include some new supplementation to the hay and pasture diet of my herd, more about this in an upcoming BLOG that will be dedicated to nutrition
MOVEMENT = LIVING ENVIRONMENT
After looking at the diet I also want to address the horse’s living environment. Does he stand around in a stall all day, a small paddock, or a pasture or larger open area? Is he alone or kept with others? What those things mean to me is does the horse get enough movement to fulfill his physical and mental needs? Does he have herd mates to fulfill his social and emotional needs? Does his paddock have an enough varied terrain to adequately stimulate his hooves? This is maybe the most important part to me. My horses live in a herd, on a track based paddock system. They have access to pasture when needed and are constantly on the move. I can regulate their feed and movement as required. None of my horses get “hot” because they are standing around all day, and they don’t get bored because their social and emotional needs are fulfilled. None of them need a “job” or need to be ridden in order to keep their cool. They live like horses, and yet I can ride and play with them as needed. I have very few instances of cribbing or pacing or any other bad habits. Those are byproducts of emotional stress that doesn’t exist in my herd. Making sure the horse’s living environment is conducive to a happy and healthy horse is important because then they are able to keep physically fit and engaged which will help with the healthy hooves we want to grow
DENTAL HEATH = BALANCE
Another huge factor is teeth. I recently went to Florida to further my knowledge and become a graduate of the Horsemanship Dentistry School. This was so important for me as I have always known there was a connection between what was happening in the mouth and the soundness in the body but I needed more information. What I learned was so mind blowing. An imbalance in the teeth will create an imbalance in the jaw that would translate to an imbalance in the neck, shoulders and feet. An imbalance on the front end will affect the hind end and so on. It becomes a cascade effect, and the best part is when I am able to feel an imbalance in the mouth, correct it and see a direct improvement in how the horse moves or behaves. Horses are so innately in tune with themselves that even just a slight dental problem can have a big effect. The dentistry school I went to teaches manual balancing without the use of sedation so that you can watch the horse respond to the changes you make. I have never quite done anything else as intimate and rewarding with my horses as putting my hand inside their unrestricted mouth. With no speculum to protect me, and no sedation to alter their state of mind, I can remove any sharp points inside their mouths and watch them lick and chew and feel the area with their tongue. That is usually followed by them pressing their head into my chest with thanks. No joke, this just gets my heart pumping.
EXERCISE = MUSCLE
The last thing I will touch on in our whole horse approach to health is riding and the subsequent muscle development. Riding can play a huge part in the health of your horse’s hooves. For instance, a balanced horse that is ridden round (not over bent) will be travelling in balance from the front end to the hind end and engaging their core muscles and therefore loading their hooves optimally. A horse ridden hollow or unbalanced will create unbalanced forces on the hooves and therefore may not wear evenly. A horse ridden very over bent will travel with too much weight on the front or hind end and not travel in a balanced manner. How the horse is conditioned to riding will also affect how he will move in the pasture or paddock. Wild horses are conditioned to move 20-40 miles per day on varied terrain and tend to build well balanced bodies and hooves. When we keep horse in domestication we inhibit their ability to move freely and they don’t always understand how to move properly because of this. We must teach them how to carry the weight of a rider and still move in balance and harmony.
HEALTHY HOOVES = HEALTHY HORSES
There are many things to consider when determining how long to go between trims. In this geographic area the standard trimming/shoeing cycle is approximately 6-8 weeks. My own scheduling is usually based around a 4-6 week cycle, though I have the odd horse or group of horses that go a little longer.
What I want to discuss in this blog is a much shorter trimming cycle that is favoured among some very successful and highly respected farriers/trimmers that I follow. What I am seeing and learning from them is that a shorter cycle is far better for the horse, and the overall health of the hooves and therefore the body and mind (My whole horse approach to health will be featured in an upcoming article) of the horse.
First lets think about the ultimate goal we have in trimming our horses hooves. For me it is to mimic the wear patterns that are demonstrated by the wild horses of the US Great Basin and other dry desert dwelling feral equines. These equines are clinically sounder then our domestic horses and have virtually no instances of founder, navicular disease and many other hoof pathologies we see so commonly in our domestic horses.
So if we can apply that principle to our trimming, our mandate would be to trim in order to mimic natural wear over varied terrain. So then the correct trim schedule would have to be based on each horse’s individual hoof wear. Because the hoof is in a perpetual state of growth, this means that immediately after trimming the hoof is already replacing that (worn) material that was removed. The goal then should be to allow the hoof to grow to the optimal length and thickness required for that individual horse. It should then be trimmed again just before it grows past optimal to a leveraging state. If it is allowed to grow too long the forces during impact and movement will start to distort the hoof. When trimming we will then have to perform what is called a rehab trim as opposed to a maintenance trim. A maintenance trim means we are just trimming excess length, and that excess has not caused the start of any breakdown or distortion of the hoof. A rehab trim means that we are correcting pathologies or distortion usually caused by excess length.
The hoof on the left shows a hoof that has grown excess length but is still balanced and not distorted. The overall length needs to come down and the break-over needs a new mustang roll, but otherwise this hoof is balanced, a maintenance trim. The hoof on the right is much longer, and has grown out of balance. The heels have moved forward and the toe is stretching forward. The frog is small and narrow and appears diseased in the central sulcus. Not an extremely distorted hoof but a rehab trim, not a maintenance trim.
The shorter trim cycle will prevent distortion and instead more closely mimic natural wear. For most horses the trimming cycle that these farriers/trimmers are finding works best is 2-4 weeks, 3 weeks being the average correct cycle for most horses. It is important to understand that because these trims are closer together there will be less material to remove. On a 3 week trim cycle there would be little need for nippers, it would really just be a rasp to maintain balance and remove the excess and possibly some knife work if the bars or frog needed addressing.
Where this interests me is with a select few horses I trim that are sensitive on hard or rocky ground immediately after a trim for about 3-5 days. Not sensitive in their paddocks or living environments, but sensitive being ridden on unforgiving ground where they otherwise would have been fine. What those horses need is for me to leave a little more material at the trim, but because I won’t be trimming them again for 4-6 weeks if I leave that extra material we are at a point of distortion before the next trim and then we are back to rehab trims as opposed to maintenance trims. However if I could trim less, and then trim the horse again in 3 weeks there would be less instances of sensitivity after the trim and less instances where the hoof gets to that distortion point before the next trim..
This is easy for me to process, however it becomes a challenge when trying to help horse owners to understand that trimming less more often is in the best interest of their horse. For the horse owner it means they are paying for trims twice as often, seeing much less of a difference in the before and after of the trims, and they are having to schedule me twice as often, taking up their valuable time.
My goal is to make this process easy and beneficial for everyone. I have started a pilot project with a few clients where I am trimming their horses every 3 weeks, and evaluating the horses’s comfort levels before the trim, immediately after and at the end of the 3 week cycle. I am also looking for any hoof distortion (if present) in order to determine the optimal length of cycle for each specific horse. I am working on a price structure that includes a reduced cost for horses that are on a maintenance trim schedule vs those that are in a constant cycle of rehab trims. This would make trimming at these shorter intervals more cost effective and because there is less material to be removed the trims would take less time. Ultimately the biggest advantage of the shorter cycle is for the horse. The closer we can mimic the natural wear pattern of the wild horse, the closer we can come to achieving the soundness seen in those wild herds and the virtually non existent hoof pathology that we so commonly see in our domestic horses.
Expectations – Having realistic expectations is very important when transitioning your horse from shod to barefoot. Expecting your horse to perform the same way barefoot as they have in shoes is unrealistic. It takes time to strengthen and built hoof health and often times the shoeing process over many years has caused much damage within hoof. It is very much the same as asking a seasoned marathon runner to compete without their running shoes. It would be uncomfortable for them to feel the hard or rocky ground under their sensitive feet for the first few times. However, given enough time the marathon runner could build adequate callous so that he could perform barefoot. Taking horses barefoot should be about the long term health of the horse, not the rider’s short term performance goals. This being said, we must still make sure that our horses are comfortable when transitioning by providing them with hoof boots when needed and correct and frequent natural trims.
Time - A hoof that has been in shoes for extended periods will take time to heal internally as well as externally. Perpetual shoeing cycles can cause contraction and atrophy of the internal energy dispersing structures of the hoof. A horse that is shod is peripherally loading the hoof, which means that only the outside rim of the hoof is impacting the ground. This causes the frog and digital cushion (a structure paramount to a healthy barefoot hoof) to atrophy and weaken. However the good news is that the digital cushion has tissue similar to stem cells within it, and given the right opportunity (ie a balanced natural trim with proper stimulation) it can regenerate. The other problem with shoes is the lack of flexibility within the hoof. A metal horse shoe cannot expand and contract like a natural hoof does so there is less flexion and movement within the hoof. Less flexion and movement results in decreased blood flow and energy dissipation leading to further tissue damage. Upon pulling the shoes and providing a natural trim circulation and flexion are immediately restored, often resulting in temporary minor discomfort for the horse as circulation is increased and blood flow is restored back to a normal state.
Environment – A barefoot horse’s living environment plays a large role in strengthening their hooves. A horse that lives on soft pasture will have a hard time building the callous needed to ride on a rocky trail without some form of hoof protection. Whereas a horse that lives on hard rocky ground will have no trouble travelling on a rocky trail as his hooves would have already been conditioned to it. Even if all you have for your horse is soft pasture or dirt, adding some river rock around water troughs or in shelters or a favorite hangout spot can be a big help. Exposure to varying surfaces is important in conditioning the hoof and building strength.
Deciding to take your horse barefoot can be a complex decision. While it is greatly beneficial to them to restore natural hoof function, you must make sure you are ready to face the challenges involved with the transition. I suggest you speak with your hoof care provider about the factors mentioned above as well as discuss the overall health of your horses’ hooves and the expected length of the transition period.
Kristi Luehr is a Barefoot Trimmer, and founder of the Okanagan School of Natural Hoof Care. She is certified by the Canadian Farrier School as well as the Oregon School of Natural Hoof Care and is also trained in Equine Massage Therapy and Equine Dentistry. Her focus is to educate owners about hoof anatomy, function and proper barefoot trimming that supports and grows healthy and functional hooves specific to each horse's individual needs.