Q: My horse became very lame without showing any signs of cracks, bruising, or having a "hot" nail. The barn manager said my horse was "graveled" and called the veterinarian. After treatment, the horse became fine, but since my horse is never on gravel, could you please explain the term?
A: The diagnosis of a graveled horse is usually not difficult. It is one that should be investigated in cases where lameness occurs shortly after the farrier has trimmed and shod a horse. Properly called suppurative pododermatitis, it is an infection that manifests itself in the sensitive parts of the hoof and sometimes undermines the sole. While the name might lead you to believe that it is caused by a piece of gravel getting into the white line of the hoof and working its way out the top of the foot at the coronary band, the actual cause more likely a particle of sand or soil that introduces bacteria to the white line area and results in an infection inside the hoof wall.
The typical scenario of a graveled horse is a horse in which an infection enters the white line area of the hoof via a close nail, or a hoof with a wall defect or separation, all of which allow soil into the softer white line area. The hoof then becomes painful, and the infection works its way up the wall of the hoof to break out as an abscess at the coronary band. It follows the path of least resistance.
"Gravel" also can occur under the bars instead of at the white line. This type of "gravel" will keep the horse off of its heel, so that it walks on its toe. This type emerges as an abscess at the bulbs of the heel instead of at the coronary band. Equally as common, both types of gravel require the same treatment regimen.
Initially the infection may occur and not bother the horse. The reason for this is that the infection starts out at the ground surface, and when it is low on the hoof, the horse is not bothered by it. However, when the infection makes its way up to the sensitive areas of the hoof, the horse becomes lame, sometimes to the extent of giving the appearance of having a broken leg! The horse often has a low grade fever.
This scenario alarms many horse owners because the horse becomes extremely lame with a very swollen leg. Congestion of the blood vessels in the leg causes tendons to become painful and swollen, mimicking a tendon injury. The horse does not want to bear any weight on it.
The first thing your veterinarian may ask when he suspects the horse might be graveled is: "Has your horse been shod recently?"
When a horse comes up lame shortly after being shod (within two weeks), it is possible that one of the nails was driven too close to the white line and allowed moist soil to enter the porous white line area. After the moist soil has penetrated the wall of the hoof, bacteria sets up housekeeping in the white line area and works its way up the hoof wall. Then, the weight bearing, or the packing from the repeated pounding of the hoof on the ground, will drive the infection higher into the foot.
Treating the graveled horse consists of pulling the offending nail or the shoe in order to find the affected area of the hoof. The infected area is trimmed and allowed to drain, which relieves the pressure. To pull the remaining infection out of the hoof, a poultice is applied to keep the infection from progressing to the coronary band. The poultice can be applied in a special boot with a nylon bottom and a cotton ankle. It consists of a mixture of two parts wheat bran to one part Epsom salt, and warm water with a tablespoon of Absorbine added to it. Every 48 hours, the poultice should be changed, and twice a day, it should be rehydrated with a two ounce syringe of warm water.
Even with the poultice in place, the infection sometimes will emerge as an abscess at the coronary band. Once drainage has begun, and the pressure is released from the hoof capsule, the horse should become sound again.
Even with a fast onset that produces black or brown pus, the horse should recover in two to four days, if the poultice is applied immediately after establishing drainage. If the infection starts from a misdriven nail, the horse should still recover in four days if the poultice is quickly applied after pulling the nail or shoe. However, if the horse is suffering from other types of hoof disease or a problem such as laminitis, then the recovery time will be longer, depending on the severity of the other problems. If the inflammation was caused by trimming the hoof too short, then it will just be a matter of time until the hoof grows out. Bute or other NSAIDs, along with the poultice, can help alleviate soreness in the absence of infection.
Typically the shoe can be re-applied two to four days after treatment begins, although it might take up to a week. After the shoe has been on for a couple of days, the horse usually is able to begin work. Take it slow and start out walking the horse, then work up to trotting.
Maintaining a regular schedule with your farrier is the best way to prevent a graveled horse. The timely trimming and resetting of shoes by a qualified farrier is important to the overall health of the hooves. Daily foot care by the owner also is very important. Treat each horse individually when it comes to scheduling a farrier's visit; some horses need attention to their hooves every four weeks, while others can go up to six weeks between visits. When it comes to graveled horses, it is usually the foot that has a little too much toe or an excessive bar that ends up being affected by this condition. With this in mind, keep your farrier trimming your horse on a regular basis.
by: Fred McCashin, VMD, MSc