The cow may lie on her breastbone with her feet beneath the body and her head turned sleepily round, with the nose resting on the right flank; or, if worse, she may be stretched full on her side, with even the head extended, though at times it is suddenly raised and again dashed back on the ground. At such times the legs, fore and hind, struggle convulsively, evidently through unconscious nervous spasm. By this time the unconsciousness is usually complete; the eyes are glazed, their pupils widely dilated, and their lids are not moved when the ball of the eye is touched with the finger. Pricking the skin with a pin also fails to bring any wincing or other response. The pulse, at first from 50 to 70 a minute, becomes weaker and more accelerated as the disease advances. The breathing is quickened, becoming more and more so with the violence of the symptoms, and at first associated with moaning (in exceptional cases, bellowing), it may, before death, become slow, deep, sighing, or rattling (stertorous). The temperature, at first usually raised, tends to become lower as stupor and utter insensibility and coma supervene. The bowels, which may have moved at the onset of the attack, become torpid or completely paralyzed, and, unless in case of improvement, they are not likely to operate again. Yet this is the result of paralysis and not of induration of the feces, as often shown by the semiliquid, pultaceous condition of the contents after death. The bladder, too, is paralyzed and fails to expel its contents. A free action of either bladder or bowels, or of both, is always a favorable symptom. The urine contains sugar, in quantity proportionate to the severity of the attack.
In nearly all cases the torpor of the digestive organs results in gastric disorder; the paunch becomes the seat of fermentation, producing gas, which causes it to bloat like a drum. There are frequent eructations of gas and liquid and solid feed, which, reaching the paralyzed throat, pass in part into the windpipe and cause inflammations of the air passages and lungs.
In the torpid form of the disease there is much less indication of fever or violence. There may be no special heat about the horns, ears, or forehead, nor any marked redness or congestion of the eyes or nose, nor engorgement of the veins of the head. The attack comes on more slowly, with apparent weakness of the hind limbs, dullness, drowsiness, suspension of rumination and appetite, and a general indifference to surrounding objects. Soon the cow lies down, or falls and is unable to rise, but for one or two days she may rest on the breastbone and hold the head in the flank without showing any disorderly movements. Meanwhile there is not only loss of muscular power and inability to stand, but also considerable dullness of sensation, pricking the skin producing no quick response, and even touching the edge of the eyelids causing no very prompt winking. Unless she gets relief, however, the case develops all the advanced symptoms of the more violent form, and the animal perishes.
In advanced and fatal cases of either form the insensibility becomes complete; no irritation of skin or eye meets any response; the eye becomes more dull and glassy; the head rests on the ground or other object; unless prevented the cow lies stretched fully on her side; the pulse is small, rapid, and finally imperceptible; the breathing is slow, deep, stertorous, and the expirations accompanied with puffing is slow, the cheeks, and death comes quietly or with accompanying struggles.
Prevention.—For such fatal disease prevention is of far more consequence than treatment. Among the most efficient preventives may be named a spare diet (amounting to actual starvation in very plethoric, heavy-milking cows) for a week before calving and at least four days after. A free access to salt and water is most important, as the salt favors drinking and the water serves to dilute the rich and dense blood. Iced water, however, is undesirable, as a chill may favor the onset of fever. A dose of Epsom salt (1 to 2 pounds) should be given 12 to 24 hours before calving is due, so that it may operate at or just before that act. In case calving has occurred unexpectedly in the heavy milker, no time should be lost in giving the purgative thereafter. A most important precaution in the fleshy, plethoric cow, or in one that has been attacked at a previous calving, is to avoid drawing any milk from the bag for 12 or 24 hours after calving. Breeders on the island of Jersey have found that this alone has almost abolished the mortality from milk fever. If Epsom salt is not at hand, saltpeter (1 ounce) should be used for several days. Daily exercise is also of importance, and, excepting in midsummer, when the heat of the sun may be injurious, the value of open air is unquestionable. Even in summer an open shed or shady grove is incomparably better than a close, stuffy stall. A rich pasture (clover especially), in May, June, or July, when at its best, is to be carefully avoided. It is better to keep the cow indoors on dry straw with plenty of salt and water than to have access to such pastures.
Treatment.—Treatment of milk fever has been completely revolutionized, with the result that a former mortality of 50 to 70 per cent has been practically abolished. Formerly the most vigorous treatment was practiced by bleeding, purging, the increase of peristalsis by eserin or pilocarpin, enemas, cold in the head, counterirritants, aconite, tartar emetic, sponging, wet-sheet packing, etc. The gross mortality, however, was not materially reduced, and nearly all that were attacked within the first two days after calving perished.
The first step in the modern treatment was made in 1897, when J. Schmidt published his successful treatment by the injection of the teats and milk ducts with a solution of iodid of potassium (1½ drams to 1 quart of water). This reduced the mortality to 17 per cent. Others followed this lead by the injection of other antiseptics (lysol, creolin, creosol, chinosol, common salt, etherized air, oxygen). These succeeded as well as the iodid solution. With the injection of gases, however, a fuller distention of the udder was usually secured, and virtually every case recovered. This suggested the full distention of the udder with common atmospheric air filtered and sterilized, and this with the most perfect success. With sterile air Schmidt-Kolding claimed 96.7 per cent recoveries in 914 cases.
In America the full distention of the udder, whether with oxygen or filtered air, has proved invariably successful in all kinds of cases, including the violent ones that set in within a few hours after calving. In 1 or 2 hours after the injection the cow has got up, had free passages from the bowels and bladder, bright expression of countenance, and some return of appetite. In my cases which had made no response for 8 hours to the iodid injection, the injection of the udder to full repletion with the gas (oxygen or air) has had immediately beneficial results. A similar full distention of the bag with a common-salt solution (0.5 to 100), or even with well-boiled water, is equally effective, but in these cases the weight of the liquid causes dragging upon the udder and a measure of discomfort which is escaped under the treatment with gas.
The value of each method depends on the fullness of distention of the udder and the arrest in larger part of the circulation and chemical changes in its tissues. This distention acts like magic, and seems hardly to admit of failure in securing a successful outcome.
It can not, however, be recommended as absolutely devoid of dangers and serious complications. To get the best results it should be applied only by one who has been trained in the careful antiseptic methods of the bacteriological laboratory. Some readers will recall the case of the injection of the udders of show cows at Toronto to impose upon the judges. The cows treated in this way had the udders infected and ruined, and several lost their lives. There is no better culture medium for septic and other germs than the first milk (colostrum) charged with albumin and retained in the warm udder. Already in the hands of veterinarians even the Schmidt treatment has produced a small proportion of cases of infective mammitis. How many more such cases will develop if this treatment becomes a popular domestic resort, applied by the dairyman himself in all sorts of surroundings and with little or no antiseptic precautions? Even then, however, the losses will by no means approach the past mortality of 50 to 70 per cent, so that the economy will be immeasurable under even the worst conditions. A fair test and judgment of this treatment, however, can be obtained only when the administrator is trustworthy and painstaking, well acquainted with bacteriological antisepsis and with the general and special pathology of the bovine animal.