SYMPTOMS.—These come on suddenly and without premonitions of disease. The animal may be attacked in the stable after having been out for a short time, after a period of rest. In the milder cases there is only some _lameness_ and _muscular trembling_ of a particular limb, generally the hind ones, without apparent cause, and on examination there is a dusky brown color of the membrane of the eye and nose, and some tenderness of the ribs when struck; the lameness may be such that the animal may be scarcely able to walk, or may even go down altogether. In other cases the horse is struck down at once from loss of motive power in the loins and hind legs after having been driven only a short time after an interval of rest. In other cases the attack is not so sudden, the animal becomes very restless, perspires freely, seems to be in violent pain, the flanks heave, the nostrils are dilated, the face pinched, the body trembles violently and shows a disposition to lie down, and very soon, if not already present, the characteristic symptoms appear. These are, _tremors_ and _violent spasmodic twitchings_ of the _large muscles of the back_, _loins_ and _hips_, ending in contractions, with more or less loss of motive power. The body trembles violently, the limbs become weak so that they sway and bend, the animal walks crouchingly behind, and soon goes down unable to support himself, the urine discharged is high-colored, thick, and has a strong ammoniacal odor; the pulse varies from 60 to 80 beats per minute, generally weak though sometimes strong; temperature from 102 to 104.5 Fahrenheit, or even higher. The bowels may be regular, and in mild attacks the appetite is not impaired. In severe cases the animal lies prostrate, plainly unable to rise, refuses to eat or drink, struggles violently in his attempts to raise himself, and coma (insensibility) may supervene; in such cases the conjunctive mucous membrane of the eyes is much congested. In _very_ violent cases the animal is suddenly struck down, struggles violently for a few hours, becomes comatose and dies. In milder cases the severe symptoms abate, but the animal does not regain the use of its limbs, and though it may eat and remain perfectly conscious, is unable to rise and ultimately dies from some complication. In favorable cases the trembling, twitches and spasms abate, the urine becomes more natural, the power of movement returns, and in a few days the animal is convalescent, often having for some time a swelling across the breast like a pad as a result of the dropsical infiltration of this depending tissue. In other cases, the loss of power in certain muscles remains for a long time, and yet in other cases cerebral complications and death may ensue as a result of defective urinary secretion.