On either side of the indentation, as if wishing to aid further than ordinarily it should in bearing the body-weight, the horn takes on an increased growth, and stands above the level of the horn surrounding it. It may, as perhaps it really is, be regarded as a form of hypertrophy, brought about by the increased work that the loss of substance in the region of the false quarter puts upon it.
So long as the sensitive structures are protected the animal remains sound. Sometimes, however, from the effects of concussion or of the body-weight, a fissure appears in the narrow veneer of horn that covers them. Into this, which, of course, is but a form of sand-crack, gravel and dirt penetrate, and so set up inflammatory changes in the keratogenous membrane. As a result suppuration ensues, and the animal is lame.
Causes.—False quarter may result from any disease of the foot that involves destruction of a portion of the coronary cushion. As we may see from a reference to Chapter III., it is from the papillae of this body that the horn tubules of the wall are secreted. Destruction of any portion of it necessarily results in a corresponding loss of horn in that position. The disease occasioning this more often than any other is perhaps quittor. It may also result from suppurating corn, from a severe tread or overreach, or from the effects of a slowly progressing suppurating coronitis.
Treatment.—A radical treatment of false quarter is not to be found. Once destruction of the secreting layer of the coronary cushion has occurred, the appearance of the fissure in the wall will always have to be reckoned with. A false quarter, therefore, not only renders the horse liable to occasional lameness, but also renders weaker that side of the hoof in which it occurs.
The only method of treatment that can be practised, therefore, is that of palliation. Seeing that the trouble the veterinary attendant will have to deal with is loss of a portion of the weight-bearing surface, his attention is immediately directed to the shoeing. As with sand-crack, so with false quarter, the frog and the bars must be called upon to take more of the body-weight than commonly they do with the ordinary shoe. The indication, then, is a bar shoe. At the same time, the bearing of the wall on the shoe on either side of the fissure should be eased by slightly paring it, and the hypertrophied horn on the outer surface of the wall removed with the rasp.
In cases where penetration of the sensitive structures has occurred, complicated with the formation of pus, the same treatment as for complicated crack is to be followed. The foot should be poulticed for several days with hot antiseptic dressings, and thorough cleansing of the infected parted brought about. Afterwards strong solutions of suitable antiseptics should be applied daily until such time as the horny covering has renewed itself. This done and the bar shoe applied, the fissure may be plugged with any effectual stopping. Either a mixture, such as Percival’s, of pitch 2 parts, tar 1 part, and resin 1 part, melted and mixed together, or one of the artificial hoof-horns may either be used with advantage.