HÆMOGLOBINÆMIA. AZOTÆMIA. AZOTURIA. HÆMOGLOBINURIA. TOXÆMIA FROM IMPERFECT HEPATIC FUNCTION.
Definition. Theories, of hysteria, uræmia, spinal myelitis, myelo-renal congestion, rheumatic lumbago, myosito-myelo-nephritis, rheumatic chill with destruction of muscle albuminoids. Yet it occurs in our semi-tropical midsummer with a temperature of 80 or 90, in spring and autumn, and rarely even in the cold, damp stable in midwinter in the absence of exercise. Constant conditions: One or more days absolute rest, preceding steady work, a strongly nitrogenous ration, continued during the rest, sudden active exertion accelerated breathing and unloading of peptones and proteids from portal vein and liver into the general circulation. Sanguineous albuminuria from excess of albuminous food, free ingestion of water, suppressed milk secretion, forced marches. Transfusion of blood. Excess of albumen dangerous, excess of red globules not dangerous. The blood concentration of diuresis or diaphoresis is not dangerous. Continuous muscle decomposition from work bars the disease. Stable miasm untenable. Poison may be drawn suddenly from the enormous mass of blood in the liver, spleen and portal system. The absence of icterus antagonizes the bile theory. Benzoic acid, unaltered peptones, and glycogen are examples of elements destructive to blood. Normal destruction of red globules in liver, spleen and bone marrow. Sudden access of resulting hæmoglobin to the blood. Other products of disintegrated globules. Poisons from food, and antitoxic action of liver in presence of glycogen. Carbon dioxide favors solution of red globules. Theories of hæmoglobinæmia in man. Lesions: Blood black, diffluent, iridescent, has no avidity for oxygen, with excess of urea and extractives, serum of clot red, globules, small, pale, distorted, not sticky, extravasations, liver, enlarged, congested, blood gorged, spleen congested, swollen: Lumbar or gluteal muscles pale, infiltrated, with loss of striation; bone marrow congested, hemorrhagic; kidneys congested infarcted; urine dark brown or red, with excess of urea and hæmoglobin. End of spinal cord has congestion or infiltration. Symptoms: History of high condition, constant work, high feeding, a day’s rest, then exercise and attack. To full life, follows flagging, droops, moves one or both hind limbs stiffly, knuckles, drags toes, crouches, trembles, perspires, breathes rapidly, is tender on back, loins, croup or thigh, muscles firm, paretic, and drops unable to rise. Urine retained, brown, red or black, sometimes glairy, later may have casts. Appetite may return. In mild cases, stiffness, lameness, with or without visible muscular lesions or tremors. Urine glairy, dense, with excess of urea and nitrogenous products. Recover under careful feeding and exercise, and relapse under original causes. Progress: May recover under rest. In bad cases accelerated breathing and recumbency forbid rest and recovery. Recovery in a few hours or after a week. Urinary casts with renal epithelium, imply nephritis and grave conditions. In persistent paresis, muscles waste. Modes of death. Mortality 20 per cent. Diagnosis, by history of onset, etc. Prevention: When highly fed and hard worked, give daily exercise, with comparative rest, reduce ration, and give laxative or diuretic. Plenty of water. Treatment: Rest, sling, diffusible stimulants, bleeding, bromides, water ad libitum, fomentations, unload liver and portal vein, purgative, eserine, barium chloride, enemata, diuretics, for remaining paresis, derivatives, strychnia, diet, laxative, non-stimulating, restore to work gradually.
Definition. An acute auto-poisoning occurring in plethoric horse on being subjected to active exertion after a period of idleness, and manifested by great nervous excitement and prostration, paresis commencing with the hind limbs and the passage of hæmoglobin in the urine.
Nature and Causes. The most varied conclusions as to the nature of this disease have been put forward by different authors. In England, Haycock called it hysteria, mistakenly supposing that it was confined to mares, and Williams attributed it to uræmic poisoning, conveniently ignoring the fact that the sudden manifestation of the most extreme symptoms in an animal which just before was in the highest apparent health and spirits contradicted the conclusion. In France (Trasbot) and Southern Europe (Csokor) it has been looked on as a spinal myelitis, a conclusion based on the disturbed innervation of the posterior extremities in the great majority of cases, but which is not always sustained by the pathological anatomy of the cord. In Germany veterinarians have viewed the disease from widely different standpoints. Haubner calls it myelo-renal-congestion (Nièren-Rückenmarks): Weinmann, a rheumatic lumbago; Dieckerhoff defines it as an acute general disease of horses, manifested by a severe parenchymatous inflammation of the skeleton muscles, with a bloody infiltration of the bone marrow, especially of the femur, and with acute nephritis and hæmoglobinuria. He attributes the attack to exposure to cold. If this were the real cause the attack would be far more common in very cold weather when the horse is suddenly exposed to cold drafts between open doors and windows, than when he is harnessed and driven so as to generate and diffuse animal heat. Yet attacks in the stable are virtually unknown, and in almost every instance the onset occurs during a short drive. Friedberger and Fröhner say that the epithet rheumatismal may be correctly applied to almost all cases that we meet in practice. They quote Goring as having produced the disease experimentally by exposure to cold, and go on to explain that rest in the stable before the attack causes the extreme sensitiveness to cold that is generated by a warm environment. The implication of the lumbar, pelvic and femoral muscles they explain by the stimulation of the nutritive metamorphosis by the action of cold on the sensitive nerves of the skin. The effect of this cutaneous irritation is exaggerated by the heat of the stable to which they have been previously subjected. The products of the destruction of the albuminoids of the muscles, pass into the blood as hæmoglobin, and produce the ulterior phenomena. The muscles of the hind quarters especially suffer because of their greater exposure and because they are subjected to the hardest work in propelling the animal machine. In this connection they quote the experiments of Lassar and Nassaroff in which sudden exposure to cold determines parenchymatous degeneration of muscles; also the cases of paroxysmal or winter hæmoglobinuria in certain susceptible men whenever they are exposed to an extremely low temperature.
There are serious objections to the acceptance of this as the essential cause, among which the following may be named:
1st. The disease is not confined to the cold season but occurs also at midsummer when the outdoor temperature is even higher than it is in the stable.
2d. In our Northern States it appears to be more common in spring and autumn or early winter, when the extreme colds have either already passed, or have not yet set in, but when the abrupt changes of weather (rain-storms, etc.) are liable to shut up the animal indoors for a day or more at a time.
3d. The popular names quoted with approval by these authors—Monday disease, Easter disease, Whitsuntide disease—indicate the prevalence in Europe also, of the malady in the milder, or more temperate seasons rather than during the prevalence of extreme cold.
4th. The fact that the disease rarely or never occurs in the stable, no matter how cold the season, how open the wooden walls or floor, nor how strong the draft between doors or windows, shows that the theory of cold as the sole or main cause must be discarded.
It is not necessary to ignore the action of cold as a concurrent factor in certain cases, or as a stimulant to reflex vaso-motor paresis, to muscular metamorphosis and the increase of hæmoglobin in the blood. It is only necessary that this should be held as subordinate and non-essential to the final result. Several other factors that are accorded a subordinate place by these writers, are so constant and so manifestly essential that they must be allotted a much more important position in the list of causes.