Apart from the fact that the rich grasses of spring produce at first intestinal congestion, and diarrhœa, with consequent disorder of the liver and kidneys, this spring affection on particular pastures suggests some special poison in the pasture as the unknown cause of the disease.
In all forms alike of this affection the nature of the soil appears to have a preponderating influence. It is the disease of the woods, and waste lands, of damp and undrained lands, of dense clays, of lands underlaid by clay or hard pan, of lands rich in vegetable humus, or vegetable moulds the decomposition of which has been hastened by the application of quicklime.
Pottier, Salomé, Wiener, and Reynal especially testify to the prevalence of hæmaturia on soils that are either dense and impermeable, or that have a subsoil of clay or hardpan.
The disease has not been traced to any definite microbe nor toxin, but there is much to suggest the necessity for inquiry in that line. The special susceptibility of animals that may be plethoric on the one hand, or in low condition on the other, would be entirely in keeping with such a view, as the debility or derangement of health would lay the system open to attack.
Symptoms. In the plethoric animal there are congested mucosæ, full, strong pulse, forcible heartbeats, full veins, accelerated breathing, colicy pains, dullness, straining frequently and the discharge of thick, red or bloody urine.
If from irritant buds and shoots, or plants, there is more depression, weakness, fever, dry skin, staring coat, coldness of the surface, tremblings, stiffness or weakness of the hind limbs, diarrhœa, followed by constipation, frequent straining and the passage of colored urine with pain. In violent cases the expulsion of bloody urine may be excessive, and the cow may die in 24 hours. From irritant plants however the quantity of urine is liable to be small, but frequently passed.
As occurring irrespective of plethora or irritants there may be at first only poor condition and debility with the passage of blood. A pink tinge may show on the froth in the milk pail, and a red precipitate on its bottom. If not anæmic at the outset they soon become so, and the pulse which was at first bounding becomes small and weak, the heart palpitates, the red mucosæ become pale. The subjects become tucked up, emaciated, weak, rough coated, the skin adherent to the bones, and the appetite and rumination impaired or lost. Sometimes colics are present.
In the milder anæmic forms it may continue for months before it causes death. In such cases it may prove intermittent.
Morbid Anatomy. In the hæmaturia of plethora the kidneys are large, congested and of a dark red, but, preserve their normal consistency and texture.
In the form associated with ingestion of irritant plants, there is congestion of the pharynx, stomachs, and intestines with hæmorrhagic spots, congestion of the liver, violent congestion of the kidneys which are of a blackish red color, and enlarged to perhaps twice the normal size, with hæmorrhagic exudations, the convoluted tubes filled with fibrinous exudate and blood globules, the pelvis red and like the bladder containing some reddish urine. The vesical mucosa may be black.