Foot-and-Mouth Disease.

What is foot-and-mouth disease?

Foot-and-mouth disease is a rare affection that occurs in sheep, cows, pigs and horses, and that occasionally seems to be transmitted to man. It manifests itself by the appearance of vesicles and bullæ in the mouth and on the feet at the margins of the hoofs and, in cows, on the udder and teats. The disease may be transferred directly to man by inoculation-thus to the butcher or to the veterinary surgeon, or it may be conveyed by milk. In man, vesicles form in the mouth, on the face, on the hands and on the feet. In the course of two or three days, the vesicles rupture, discharging opaque, yellowish fluid, and leaving dark-red ulcers. There are also fever, loss of appetite, pain in eating, swelling of the tongue, fetor of the breath, salivation and derangement of digestion. In children the disease may prove fatal.

Hydatid Disease.

What is hydatid disease?

An hydatid cyst is a parasitic formation due to ingestion of the ova of the tenia echinococcus, the tape-worm of dogs, in which it is derived from the flesh of sheep, or pigs, or less frequently, kine, suffering from hydatid disease.

When the ovum enters the stomach of man, its capsule is dissolved, and the immature embryo or scolex (Fig. 16) is set free to continue its migrations. Arriving at its destination, the irritation to which it gives rise results in the formation of a membranous envelop, in which the parasite continues its development. This capsule, and its contents together constitute an hydatid cyst. An hydatid cyst contains within the capsule, a vesicle or mother-sac, consisting of concentric layers of a gelatinous material, inclosing the embryo and more or less fluid. The fluid is clear, opalescent, and faintly alkaline. Within this develop other similar sacs, so-called daughter-vesicles, and

within these again, granddaughter-vesicles; the mother-sac and its investing membrane continue to enlarge, if in a favorable situation, until ultimately the cyst attains an enormous size. Multiple cysts may form. The daughter-vesicles contain

Tenia Echinococcus-vesicle, scolex and hooks. (After Heller.)

a germinating layer that produces new scolices. These consist of a head, four suckers and a row of hooklets. The discovery of the hooklets (Fig. 16) in fluid removed from the cyst is diagnostic. Sterile echinococci or acephalocysts do not produce scolices.

Hydatids may develop in various viscera, but are most common in the liver.

What is trichiniasis?

Trichiniasis.

Trichiniasis is a disease set up by the trichina spiralis (Fig. 17), a small roundworm that finds its way into the intestine with meat obtained from diseased swine.

In the intestine the mature female throws off embryos, which pass through the walls of the intestine and into the blood-current, finding their way into the voluntary muscles in different parts of the body. Here the embryos occasion irritation and inflammation, so that about each a capsule forms in which lime-salts are in time deposited; in this way the death of the embryo may be brought about.

What are the symptoms of trichiniasis?

FIG. 17.

The symptoms of trichiniasis present themselves in three stages. In the first, which lasts about a week, the trichinæ are undergoing development in the alimentary canal, as a result of which the symptoms of gastro-intestinal derangement appear. In the second stage, lasting two or three weeks, the embryos pass from the intestine into the muscular tissue. Finally, retrogressive changes take place in and around the trichinae encapsulated in the muscles.

In the first stage, the appetite is impaired; the tongue is coated, the breath is foul; there are malaise, nausea, a bad taste, diarrhea, abdominal pain and slight fever.

In the second stage, there is edema, apparent in the face and sometimes extending downwards; there are also pains in the muscles, which are swollen; defects of the. ocular muscles and of accommodation sometimes appear; the senses and various functions may be affected; sleep is disturbed and there is moderate fever. The muscles are sensitive to touch, which may detect the minute nodules. Death may result from exhaustion, pneumonia or ulceration of the bowel. In favorable cases, the symptoms gradually subside and the patient enters upon the third stage of the disease. Active symptoms are now in abeyance, but there may be some stiffness of the muscles, while nodules in the muscles may be detectable.

Trichina. a, Male; b, Female; c, Muscle-Trichina. (V. Jaksch)

Ultimately, however, the patient may be restored to a fair degree of health.

Acute Rheumatism-Rheumatic Fever.

What are the symptoms of acute rheumatism?

Acute rheumatism or rheumatic fever usually follows exposure to cold. An almost identical condition is sometimes observed in the course of puerperal fever and as a sequel of scarlatina. It is thought to be dependent upon the presence of lactic acid in the blood. One of the larger joints becomes painful, enlarged, hot and reddened. It is evidently inflamed; sometimes the presence of fluid can be detected. Soon, another joint, probably the corresponding joint on the opposite side, or the next contiguous joint, becomes similarly involved; and in this way the process may extend, until most or all of the large joints are in turn attacked. On account of the pain, the patient is immovably helpless. From the surface of the body exudes an acid sweat. The temperature ordinarily ranges from 102° F. to 104° F., rising with each fresh access of joint-symptoms, and declining gradually with the termination of the disease. The pulse is disproportionately frequent; it may be full and bounding. The urine is scanty, high-colored, and quite acid; it may contain a trace of albumin.

In many cases, to the articular manifestations endocarditis is added, as a result of which permanent valvular lesions may be established. Among other complications are inflammations of the pericardium, the pleura, the peritoneum, the kidney and, though rarely, the cerebro-spinal meninges. As a rule, delirium is due to the toxemia and not to meningitis.

Sometimes the temperature rises even to hyperpyrexia, and there are decided cerebral symptoms-delirium, convulsions, coma, death.

Untreated, the duration of acute rheumatism is about six weeks; sometimes much longer. Relapses are not uncommon. An attack predisposes to subsequent attacks.

Purpura is sometimes seen in the course of rheumatism; sometimes tuberculated cutaneous nodules.

In some cases of rheumatism, hereditary influences can be traced. Some authorities consider the disease a dyscrasia, others

a neurosis. There appears to be an indefinable, yet close relation between acute rheumatism and chorea.

Articular rheumatism not uncommonly accompanies, precedes or follows acute tonsillitis. In such cases, pericarditis and endocarditis may sometimes be detected if carefully searched

for.

How are pyemia and acute rheumatism to be differentiated?

Both pyemia and acute rheumatism occasion arthritis, sweats, cardiac complications and cerebral symptoms. Periodicity and rigors, as well as metastatic invasion of internal structures remote from the primary seat of disease, which are common in pyemia, are wanting in rheumatism. The constitutional depression is more profound in pyemia than in rheumatism. In one, an obvious or obscure focus of suppuration exists; in the other, there is a history of rather abrupt onset following exposure to cold or wet.

How are acute synovitis and acute rheumatism to be differentiated ?

Acute synovitis usually involves but a single joint; it is characteristic of acute rheumatism to progressively attack many joints. The constitutional phenomena are more profound in acute rheumatism than in acute synovitis.

The peculiar, acid sweats, as well as the cardiac complications of rheumatism are not seen in synovitis.

In duration, synovitis is the shorter disease.

Gonorrheal Synovitis,

What is gonorrheal synovitis?

Occasionally, in the course of an attack of gonorrhea, a large joint-and usually but one joint, such as the knee, the elbow, the wrist, the ankle or the shoulder, becomes tumid, painful, tender and hot, and the adjacent textures may be edematous. The urethral discharge often ceases with the appearance of the synovitis. In successive attacks of gonorrhea, different joints may be involved. Permanent stiffness and impaired mobility constitute a common sequel. Cardiac complications have been