Many diseases of the skin pass by this name, though the most common is perhaps nettle-rash, which appears suddenly as an eruption of hard lumps, or weals, on different parts of the body; itching is also present, and the hair often falls off. In a few days the symptoms disappear.
This condition is usually brought about by derangement of the stomach, or it may be due to exposure to a hot sun, cold wind, standing in draughts when over-heated, or from the horse drinking cold water when hot.
The treatment will depend upon the cause. If surfeit arises from indigestion, a mild dose of physic with sloppy diet, with an ounce or two of bicarbonate of soda once or twice a day in it, will effect a cure. If the eruption becomes chronic, tonic medicines should be given. The body should be well clothed.
A constitutional form of surfeit is sometimes seen, and is very troublesome. Little blisters form on the body, which burst and crust over; and at the same time there is great itching, causing the horse to rub and bite himself.
Great attention should be paid to the diet, which should be more or less laxative, and nitrate of potass should be frequently given. Liquor arsenicalis is useful mixed with the food - about an ounce daily. Lead lotions to the skin allay the itching, or even ordinary vinegar (one part to twenty of water) will have the same effect. A linen sheet worn beneath the woollen one is advantageous.