A foot infection can also produce a transverse crack as the result of the infection forcing its way up the sensitive laminae and bursting out through the coronary band, again interrupting the growth of the wall.

CAUSES
The lack of regular trimming is the most common cause of grass cracks, along with a weakness in the hoof wall. Sand cracks occur as a result of trauma to the Coronary Band by injury, such as overreaching, interference from the other feet, or lacerations. These create a weak deformity in the wall. There can also be a congenital deformity resulting in a weak fault line. Dry feet tend to be less flexible and crack more easily as a result.

CLINICAL SIGNS
Apart from the obvious split in the wall the horse may or may not be lame depending on whether the sensitive laminae are involved. There may be blood or exudate in the crack, a fair indication of sensitive laminae involvement.

TREATMENT
In the case of an infected crack a good draining hole should be cut as low down the wall as possible. You're vet would probably administer antibiotics. Covering over is not a good idea as this can entrap any infections, although sometimes an acrylic filler is necessary. In this case a plastic tube can be inserted to administer oral antiseptics or to retain a drain hole.

PROGNOSIS
Grass cracks are generally speaking easy to deal with by trimming or shoeing. However, sand cracks are more difficult as the normally very flexible area at the coronary band has to be stabilised to stop the crack from being aggravated. Seedy toe, a fungal infection of the white line (sometimes referred to as white line disease) unfortunately often goes hand in hand with these cracks. This looks like a black hole, which if explored with a nail produces a powdery pulp (like seeds, hence "seedy toe"). If the hole is not deep, just cleaning it out every time the horse is trimmed or shod, and an astringent applied or surgical spirits or purple spray etc., thus keeping ahead of seedy toe. The horn growth can be faster than the advancement of the fungal infection. If not, complete removal of the affected area and exposure to air is the only other way we can deal with this.

GRASS CRACKS - FARRIERY

Generally speaking trimming, sometimes quite hard trimming will cure this problem. This relieves the pressure that has caused the crack. (insert "grass crack trim jpg") If a crack has got very bad shoeing with extra clips to stabilise the area can prevent the bending action of the wall which has created the problem.

SAND CRACKS - FARRIERY

Treatment involves generally three techniques · Plating - This involves screwing a long narrow plate across the crack with 4 short screws into the wall. This stabilises the crack long enough to allow the coronary band to repair and grow new hoof wall. ( insert "san cr plating jpg")

There are some variations on the market which makes the job a lot easier, they work on the same principle.

· Stitching - This involves drilling horizontally behind the crack to enable a series of horseshoe nails to be driven through and out the other side thus creating stitches, which can be clenched up. About four stitches can be used and glued up when finished.

· Glueing - This involves a simple plastic tab which is glued with a powerful glue over the crack, again to stabilise it. Obviously the rough and tumble environment of the horse is not ideal for this as it can be wrenched off.

All these techniques are done with weight bearing on the affected foot as this closes the crack offering the best possible start to the repair process.


Author - Tom Knox DWCF