A constitutional disease supposed to be due to an excess of lactic or some other acid in the blood. It is most prevalent during wet or changeable weather; it is often caused by exposure to cold; some animals seem predisposed to it and an attack will come on apparently without any exciting cause.

Symptoms. - The animal is suddenly attacked with lameness either with or without swelling. Sometimes the lameness will shift from one leg to another in twenty-four hours. The affected part is very tender on pressure; the pulse is hard and rapid and the temperature is elevated. Rheumatic patients generally give forth a sharp, clicking sound from the joints when first starting to walk after standing a few minutes.

Treatment. - Bathe the affected joint with hot salt-water several times a day, and after wiping dry each time rub on a little of the following: Sweet oil, ammonia, turpentine, oil of origanum, spirits of camphor and fluid extract of belladona, of each, two ounces. Give internally a dose of aloes sufficient to open the bowels, then give the following dose three times a day:

Bicarbonate of potash, two to four drachms; powdered colchicum seed, one-half to one drachm; mix. Vary the amount of the dose to suit the size of the horse. Keep the animal loose in a roomy, warm, but well-ventilated box stall. Feed on soft food of a laxative character.