The diseases which are included in this division are increased sensibility, diminished sensibility, and perverted sensibility. The last of these is known in the horse as pruritus, which is really, as the word indicates, itching without any recognizable cause; there is no detectable eruption nor any redness save what may result from the part being scratched, in fact itching is the only symptom which has to be dealt with by remedies. In many cases the itching is so excessive that in the language of the groom the horse is driven nearly mad, and in his excitement he tears his clothing, and increases the irritation by rubbing or scratching, causing an eruption and erosions in various parts of the body.

The treatment of the disease, which is necessarily associated with general systematic derangement, belongs more properly to the domain of general medicine, but for the alleviation of the annoying irritation local remedies are indispensable. Dr. James Law of the Cornell University recommends a wash of water slightly soured with oil of vitriol, and rendered sweet by carbolic acid. If this acid lotion fails to afford relief, an alkaline and sedative mixture may be employed instead - for example, 2 drachms of carbonate of potash and 2 grains of cyanide of potassium in 1 quart of water. It is of the first importance that the diet be carefully regulated and the work be duly adjusted to it. Excess of highly stimulating food must be guarded against. A liberal allowance of carrots and moist bran will prove useful in maintaining a free and regular action of the bowels. Where constipation exists a dose of physic may be required, and should the disease prove obstinate an ounce of Fowler's solution of arsenic must be administered morning and evening in the food.

Fig. 270. - Sallanders.

Fig. 271. - Mallenders.