_Treatment._ The prophylactics and therapeutics of vertigo will vary with the cause. The diagnosis of the cause is therefore the most important step. In pampered, overfed, idle horses a reduced ration and daily exercise or work will often suffice. It is usually desirable, however, to remove intestinal irritants and deplete the vascular system by an active purgative. If the attacks appear only in Spring this care should be especially given at such seasons. A tight or badly fitting collar should be corrected, also a position of the breast strap which causes it to press on the jugular veins. A short bearing rein causing undue flexion of the head must be lengthened or abandoned. A too dark stable should be avoided, also the sudden exposure to white, dusty roads and, still more so, to the glare of snow, ice, or water. A short, overdraw check rein, turning the eyes up directly into the sun’s rays, or blinds with a glistening inner surface may require correction. It may be better to abandon blinds altogether, or to cover the eyes by a piece of leather, 2 to 4 inches wide, extending across the forehead from one eye to the other; or a sunshade attached to the headstall may be worn so as to protect the eyes. Horses which become seasick or carsick may sometimes be helped by covering the eyes. Other indications would be to treat any existing trouble which interferes with a normal circulation in the brain (pulmonary congestion, aneurisms, tumors pressing on carotids or jugulars, phlebitis, etc.), and such as affect the ear (disease of the pharynx, guttural pouches, adjacent glands, petrous temporal bone, membrana tympani, external ear). Indurated wax, insects or insect larvæ may be removed by careful irrigation with warm water, and perhaps by chloroform. Nasal parasites must be washed out or destroyed by benzine, and any hyperæsthesia of the nasal mucosa may be met by covering the nostril with a net, or radically by cutting the facial branch of the 5th nerve as it emerges from the infra-orbital foramen. When attacked the horse should be at once stopped and put under the shadow of a roof or tree, or in their absence a blanket or lap robe may be used to cover his eyes. If there is danger of falling remove the harness, and secure a soft piece of ground, free from stones or other hard bodies. Cold water applied to the head will sometimes check. A common practice is to bleed from the palate, and in plethoric cases especially, and in such as are dependent on congestion, tumors or other lesion of the brain it is to be commended. The action will be rendered more prompt and effective if the blood is taken from the jugular. A laxative diet, and carefully regulated work are desirable to obviate the tendency to the affection, and this may often be accomplished by a run at pasture. Otherwise daily small doses of Glauber salts in the feed may suffice. Bromides may be used to calm nervous excitement.