The blackness and thickness of the blood has been noted by practically all observers. This is partly the result of its density, but doubtless also of the undetermined toxins which are operative in the disease.
Yellowish gelatinoid exudates have been found in the subdorsal and sublumbar regions, as well as the cranium and spinal canal.
Glucose appears to be constantly present in the urine, and in excess in the more violent and fatal cases: from 1.19 grm. per litre in slight cases to 41.8 grms. in a fatal one (Nocard). Albumen may be present, though probably only when local inflammation has supervened.
Symptoms. The conditions of the attack should be noted. This is a disease of the first six days after parturition, rarely seen in the second week, and never after the fourteenth day. It is very exceptional before parturition, yet Müller quotes 47 cases in 1107 births. The breed, condition, milking qualities, plethora, feeding, etc., of the patient are, as already noted important data in diagnosis. The onset is sudden without premonitory symptoms.
Two very distinct types are met with, the comatose and violent or spasmodic, which, however, merge into each other by insensible gradations, and may follow each other.
From twelve to seventy hours after an easy parturition there suddenly appear signs of discomfort. Feeding and rumination cease, the calf is neglected, there may be plaintive moaning, the eyes seem dull and clouded, the eyelids drooped, the conjunctiva red, the pulse normal for parturition, sometimes extra strong, the breathing excited often with moans or grunts. The senses are dulled, the walk is unsteady, the feet being abducted and planted like clumps, or the legs sway, perhaps cross each other, remain semi-bent, and soon give way leaving the animal prostrate, resting on the sternum and abdomen, or later on the ribs, with head extended. Attempts may still be made to rise, but this is rarely accomplished unless when improvement sets in. This is the condition in which the patient is usually found, being the first to be noticed by the owner. The bowels are torpid, the urine retained in the bladder, and the animal may remain thus in a drowsy condition, without changing from the sterno-ventral decubitus, or dropping the head on the ground until improvement sets in. The head rests on the shoulder or upper flank. If held outward or forward the upper border of the neck has an S shaped outline.
More commonly the somnolence increases, passing into a complete torpor and insensibility, the eye may be touched without causing winking, pricking or other injury causes no further response, the patient turns upon its side, with its head extended on the ground. She may lie in this condition with no sign of vital activity save pulsation and breathing, and the latter is liable to be slow and stertorous by reason of the paralysis of soft palate and larynx. The jugulars usually show a venous pulse. Fermentations in the inactive paunch cause the evolution of gas with tympany, which still further obstructs the breathing, and reacts injuriously on the nerve centres. The normal eructations from the rumen may continue, with liquids and floating solids, and in the paralytic state of the throat these too often pass in part into the bronchia, causing septic bronchitis and pneumonia. The same is liable to follow the administration of liquids, the irritant drugs passing into the larynx, trachea and lungs. The pulse becomes soft, small and finally almost imperceptible. It may be 50, 60 and upward.
In favorable cases, defecation may still occur, or the rectum once emptied may fill again through the continuance of peristalsis, the milk continues to be secreted, and in one to four days, spontaneous defecation and micturition may be resumed, and the patient may get on its limbs and commence feeding. There is usually at first a little weakness of the limbs, but this is transient and health is restored in a very short time. The suddenness of the improvement is often as marked as of the attack. The patient is left prostrate and insensible, without giving any response when the eyeball is touched and in two or three hours it is found on its feet, eating, with eyes bright and clear.
Some patients, however, are restored to ordinary sensation, intelligence and appetite, while the hind limbs remain paralytic, or paretic, and the station and gait both weak and uncertain for days or even weeks. In such cases there have been presumably structural changes in the nerve centres, which require time for repair.
In fatal cases, death may occur quietly from apoplexy, cerebral compression, or narcotism, or it may be preceded by a period of marked excitement or disorderly muscular movements. Lifting of the head, throwing it alternately on the shoulder and on the ground, trembling of head, members and body, cramps or jerking of the limbs or of other parts, drawing the hind limbs up against the abdomen, and again extending them, rolling of the eyes, loud, noisy, irregular, embarrassed breathing and a running down pulse are often marked features.