As the disease approaches the fatal termination the weakness of the animal increases. It leans against supports or lies down. Blood vessels may rupture and give rise to spots of blood on the various mucous membranes and bloody discharges from nose, mouth, rectum, and vagina. The urine not infrequently contains blood (red water), and death ensues within one or two days.
A third type of the disease (anthrax subacutus), which is rarely observed, includes those cases in which the disease is more prolonged. It may last from three to seven days and terminate fatally or end in recovery. In this type, the symptoms are practically as described in the acute form, only less marked.
In connection with these types of intestinal anthrax, swellings may appear in different parts of the body under the skin, or the disease may start from such a swelling, caused by the inoculation of anthrax spores in one of the several different ways already described. If the disease begins in the skin, it agrees in general with the subacute form in prolonged duration, and it may occasionally terminate in recovery if the swellings are thoroughly incised and treated.
Lesions.—These swellings appear as edemas and carbuncles. The former are doughy tumors of a more or less flattish form passing gradually into the surrounding healthy tissue. As a rule, they are situated beneath the skin in the fatty layer, and the skin itself is at first of healthy appearance, so that they are often overlooked, especially when covered with a good coat of hair. When they are cut open they are found to consist of a peculiar, jellylike mass of a yellowish color and more or less stained with blood. The carbuncles are firm, hot, tender swellings, which later become cool and painless and undergo mortification. The edemas and carbuncles may also appear in the mouth, pharynx, larynx, in the tongue, and in the rectum.
The bodies of cattle which have died of anthrax soon lose their rigidity and become bloated, because decomposition sets in very rapidly. From the mouth, nose, and anus bloodstained fluid flows in small quantities. When such carcasses are opened and examined it is found that nearly all organs are sprinkled with spots of blood or extravasations of various sizes. The spleen is enlarged from two to five times, the pulp blackish and soft and occasionally disintegrated. The blood is of tarry consistency, not firmly coagulated, and blackish in color. In the abdomen, the thoracic cavity, and in the pericardium, or bag surrounding the heart, more or less blood-stained fluid is present. In addition to these characteristic signs, the carbuncles and swellings under the skin, already described, will aid in determining the true nature of the disease. The most reliable method of diagnosis is the examination of the blood and tissues for anthrax bacilli, which requires a trained bacteriologist. The cases of fatal anthrax number from 70 to 90 per cent, and are usually more numerous at the first outbreak of the disease.
Differential diagnosis.—The diagnosis from blackleg may be made by noting the subcutaneous swellings which appear upon the patient. Those of blackleg are found to crackle under pressure with the finger, owing to the presence of gas within the tissues, while the tumors of anthrax, being caused by the pressure of serum, are entirely free from this quality and have a somewhat doughy consistence. The tumors of blackleg are usually on the shoulder or thigh and are not found so frequently about the neck and side of the body as are the swellings of anthrax. The blood of animals dead of blackleg is normal, and the spleen does not appear swollen or darkened, as in those affected with anthrax. The chief differences between anthrax and Texas fever are that the course of the former is more acute and the blood of the animal is dark and of a tarlike consistence, while in the latter it is thinner than normal. The presence of Texas-fever ticks on the cattle would also lead one to suspect that disease in regions where cattle are not immune from it.
Treatment.—In cases which originate from external wounds, the swellings should be opened freely by long incisions with a sharp knife and washed several times daily with carbolic-acid solution (1 ounce to a quart of water). Care should be taken to disinfect thoroughly any fluid discharge that may follow the incision. When suppuration has set in the treatment recommended in the chapter on wounds should be carried out.
In the treatment of animals showing symptoms of anthrax, the serum recommended under the next heading of "Prevention" should be administered in large doses. Animals showing only a high temperature with no other symptoms of the disease should be given from 30 to 50 cubic centimeters of the serum, but if the gravity of the disease is pronounced 100 cubic centimeters should be administered. In most instances a drop in temperature may be observed and a diminishing of the severity of the symptoms. At times, however, a relapse occurs about the second or third day following the serum injection, when it becomes necessary to administer another dose of serum. It has been proved that animals affected with anthrax may recover after injections of potent serum.
Prevention.—In this disease prevention is the most important subject demanding consideration. The various means to be suggested may be brought under two heads: (1) The surroundings of the animal, and (2) preventive inoculation.
(1) Surroundings.—What has already been stated of those conditions of the pastures which are favorable to anthrax, after a little thought, will suggest to most minds some of the preventive measures which may be of service in reducing losses in anthrax localities. All that conduces to a better state of the soil should be attempted. The State or Nation, by appropriate engineering, should do its share in preventing frequent inundations. If pools of stagnant water exist in the pastures, or if any particular portions are known by experience to give rise to anthrax, they should be fenced off. Efforts should likewise be made toward the proper draining of swamp lands frequented by cattle. Sometimes it has been found desirable to abandon for a season any infected or dangerous pastures. This remedy can not be carried out by most farmers, and it is liable to extend the infected territory. In some instances withdrawal of cattle from pastures entirely and feeding them in stables is said to have reduced the losses.