Thrush is a bacterial infection that thrives in wet and/or unsanitary environments and damages the hoof, frog and heel bulbs. It creates voids in the hoof and frog and proliferates, with a wide range of severity. If hooves are not picked out regularly, the likelihood of thrush developing increases. It is commonly found in horses that have upright, narrow feet, feet with deep clefts and on horses with hoof imbalances such as sheared heels.
Symptoms: A foul odour from the horse’s foot or a greyish, chalky appearance of the sole, are signs that the hoof needs attention. The presence of a black, gooey material (F. Necrophorum bacteria) indicates that infection is rapidly taking over, and deterioration of the hoof has begun. At this point, there can be pain associated with the exposure of sensitive tissue, and risk of internal infection. Note that where separation of the hoof wall has occurred, such as in horses with laminitis, for example, thrush can also make its way into these voids, creating a prime environment for white line disease. White line disease occurs when opportunistic bacteria and/or fungus attack the white line of the hoof (where the hoof wall meets the sole), typically causing a small separation in the white line, which can spread if not attended to.
Farrier Fix: Your farrier will trim the hoof so that most of the infected area is cut away. This will expose the pocket of thrush and voids in the hoof wall to oxygen, which will not allow the bacteria to survive.
At-Home Treatment: Daily cleaning of the frog and sole with a stiff bristle brush and application of commercially-made topical products or a seven per cent iodine spray is recommended. Thrush between the bulbs of the heels is often seen in horses with hoof imbalances such as club feet and sheared heels. These cases can be treated by flossing between the bulbs with gauze until no more black material comes out, and then putting a topical ointment on a new piece of gauze and stuffing it in the crevice. The gauze must be changed daily until the odour and black material disappears. Using copper sulphate with zinc oxide cream, commercially-prepared iodine gel or Tolnoxequine cream is recommended.
Prevention: You can reduce the likelihood of thrush by ensuring a clean environment, regular hoof care by a professional, exercise to stimulate a healthy hoof and promote self-cleaning, and daily cleaning of the hoof.
Horizontal cracks are usually the result of damage to the hoof caused by impact or an abscess, and don’t require intervention. With vertical cracks, however, your farrier will need to assess the depth and severity before coming up with a treatment plan. The farrier needs to figure out why the crack has started. Most often it is a case of too much hoof flare or poor hoof angles causing uneven and undue leverage that have not been addressed. Other causes include an over-grown hoof, injury to the coronary band, white line disease, poor quality of horn, an imbalanced or stressed hoof or drastic change of environment (such as from very wet to very dry).
Symptoms: A superficial crack doesn’t go through to full thickness of the hoof wall and is likely just cosmetic. A deep crack is more severe. It can travel up or down the hoof wall, and penetrate the full thickness of the wall, allowing bacteria to enter the sensitive tissue, and the hoof to move in two separate parts instead of a single unit, both of which can cause lameness.
Farrier Fix: If the crack has penetrated the coronary band, urgent care is needed. If left unattended, a permanent fault line in the hoof can develop. Your farrier will trim off any flares, thus reducing the stress placed on the foot from the ground surface. Support in the form of a shoe or pad is usually used to help off-load the
At-Home Treatment: Monitor the crack to make sure it doesn’t get worse, and call your farrier or trimmer in promptly if it does.
Prevention: Provide proper nutrition, ensure good footing and stick to a regular trim schedule. Cracks on unshod feet can usually be managed by frequently trimming the feet: try every four to six weeks instead of six to eight weeks.
Bruising can occur in the wall, the frog, the white line or the sole. The sole is the part of the hoof that most frequently bruises, and the term, ‘stone bruise’ is often used in this instance. The most common cause of a bruise is impact with hard ground or stones. Horses that are ridden on rocky terrain or have rough pastures are likely to get the occasional bruise, but horses that are thin-soled or have soft feet can bruise even on soft ground. Thoroughbreds, for example, often have very thins soles. Wet conditions cause the soles to soften, also making them more prone to bruising. It is very common to see bruising during the hot summer months when flies are bad and horses are stomping their feet most of the day. Light bruising is also common in the winter, when horses spend a lot of time pawing at frozen ground looking for grass.
Symptoms: Lameness on the affected foot is the most obvious sign of a stone bruise. The horse may appear sensitive or have a head bob when the bruised foot is in the weight bearing phase of the stride. Don’t expect to see the obvious discolouration of a bruise on the sole. Bruising can take time to be visible and it would usually be the farrier that would discover it during a trim.
Farrier Fix: To provide relief from a bruise, a shoe can be applied. This helps by lifting the sensitive part of the hoof further from the ground and protecting the bruise. If the bruise is bad or the sole is very thin, a pad can be put under the shoe to protect the whole sole. A barefoot trimmer might advise hoof boots with or without a pad inside to protect and
cushion the sole.
At-Home Treatment: There isn’t much you can do to treat a bruise, and it is mostly a waiting game to allow the bruise to heal. It is more important to prevent future bruises if the horse is prone to them.
Prevention: The easiest way to prevent bruising is by avoiding excessively rocky terrain and riding carefully when it is not avoidable. If a horse has soft soles, an easy step for owners to take is to apply a hoof hardener such as Keratex®, or drying agents such as Venice turpentine or iodine to the sole of the foot two to three times a week, which will harden the bottom of the foot. If this is not enough to prevent bruising, more protection is necessary and protective boots or shoes are the next step. Removable boots are great for trail riders that rarely need the protection of a shoe, but might be on rough terrain occasionally. Shoes may be more suitable for performance horses or horses that frequently need protection. Finally, if shoes are not enough to prevent bruising, adding a leather or plastic pad with a silicone-like material may help.
An abscess is an infection of the sensitive tissue of the hoof, which can make a horse lame to varying degrees. They are often caused by bruises that turn necrotic, or by puncture wounds. They can even be caused by alternating wet and dry conditions that cause the white line to expand and contract allowing bacteria to enter and become trapped.
Symptoms: Some horses show no signs of having an abscess and the farrier will be the first to discover it. Often, however, a horse will show extreme lameness on the affected limb. There will usually be heat in the hoof and the horse will have a reaction to isolated pressure from hoof testers, which are a tool that gives a precise isolated pressure over any chosen part of the foot. Sometimes the lower limb will even swell up.
Farrier Fix: Your farrier will use hoof testers and go through a procedure of testing the whole hoof trying to find an area that causes a reaction from the horse. This will usually indicate where the abscess is located and then the farrier can carefully use the knife to pare dead sole and drain the abscess. If the abscess is close to the surface, the pus will drain from the abscess tract. If it is still too deep within the foot it is best not to dig a deep hole trying to find it.
At-Home Treatment: If the abscess is can’t be located, it is recommended to soak the foot in Epsom salts and to poultice the foot. Abscesses can break out the bottom of the hoof or exit at the coronary band. It is preferable if they exit through the sole because this will cause the least disturbance to the hoof. When they break through at the coronary band, the disturbance will cause a horizontal crack or cleft that will grow down the length of the hoof; a cleft will become a weak spot as it nears the bottom of the hoof. Soaking and poulticing the foot will soften the sole and encourage the pus to draw towards the bottom. Once the abscess has broken open, it is important to sterilize the opening with iodine or hydrogen peroxide.
Prevention: Abscesses can be difficult to prevent. Many of the same precautions for preventing bruises should be applied here. Use common sense regarding the terrain that a horse is worked on, and ensure paddocks are free of debris that can puncture the sole such as nails or glass.
Chips on the hoof wall are rarely seen in shod horses, except in overgrown toes. In barefoot horses they can be a result of neglect or from the foot not being trimmed regularly, but it can be normal for small fragments of the wall to be worn away or chipped slightly if the horse is travelling on rough and rocky terrain. In the wild, horses move 15 to 25 miles on average a day, self-trimming their hooves, while domestic horses are often housed in stalls or small confined areas where the ground is soft and proper movement is limited. If the bottom of the hoof wall is left flat from a trim and not rounded on the edges, the wall is prone to chipping. Nail holes left from shoeing the hoof leave the wall weak and susceptible to bacteria and fungus. If you see chipping, peeling and cracks, it may be an indication that the horse’s immune system is compromised. Mineral deficiency or imbalances in minerals as well as stress can also have a negative impact on the hoof.
Symptoms: Layers of the hoof wall can begin to peel apart, leaving a jagged appearance to the hoof. The size and depth of can vary.
Farrier Fix: Trimming more frequently and, if barefoot, trimming to the wild horse model and following the live sole allows each hoof to grow to what the individual horse needs without imposing standards or angles and gives optimum protection to the natural hoof. The ‘mustang roll’ rounds the wall off, making the breakover in all directions much smoother. Trimmers and farriers are the first line of defence if they understand what the hoof is telling them and can help direct the owner on changes to help the horse and hoof.
At-Home Treatment: The use of boots with pads will protect the horse’s hoof while you work at balancing the diet and increasing movement. Soaking the hoof for 20 minutes in one part apple cider vinegar and two parts water can cleanse the hoof and kill bacteria. If it the hoof is badly infected, you can use the fungicide Clean Trax.
Prevention: Whenever possible, have your hay tested and the minerals balanced, and have the horse trimmed on a regular four- or six-week cycle.
Thank you to farriers Nicholas Spencer of Langley, B.C., and Jonathan Taylor of Cobourg, Ontario, as well as natural hoof care practitioner Anne Riddell of Barrie, Ontario, for their contributions to this article.