Part 12

In chronic cases the lesions are mostly shown in the lungs and lymph glands. The lungs show circumscribed lobular islets of congestion, induration or caseation, offering a suggestion of tubercle, which is all the more deceptive when cretifaction has set in. The caseous centres may vary in size from a pea to a walnut, and some may have ruptured to form a vomica discharging into a bronchium. Bronchia leading to affected lobules are blocked with muco-purulent matter, yellowish, thick and tenacious, and their mucosa is thickened and puckered. The enlarged lymph glands are especially those of the bronchia, trachea, mediastinum, bowels, mesentery and sublumbar region.

The bacillus is present in the exudate but is especially abundant in the blood, and in the chronic cases in the bronchial mucous.

Diagnosis. From anthrax (gloss-anthrax) this affection is easily distinguished by the absence from the blood and exudates of the large, square ended anthrax bacillus, by the absence of enlargement and blood engorgement of the spleen, and of the softness and diffluence of the blood clot which characterize anthrax. Swine which are with difficulty inoculated with anthrax are very susceptible to hæmorrhagic septicæmia. Sheep which are very receptive to anthrax are somewhat refractory to the disease now in hand. Pigeons resist anthrax but readily contract septicæmia hæmorrhagica.

From black quarter it is readily distinguished by the absence of emphysema and crepitation and of a secondary cooling in the external swellings, by the presence of the germ in abundance in the blood, by its smaller size, its bipolar staining, and its lack of motility and of spores. Inoculation with black quarter bacillus kills the guinea pig, but spares the pigeon.

From lung plague it is distinguished by the suddenness of its attack and rapidity of its progress to a fatal issue; by the usual coincidence of skin and bowel lesions, while the lung plague affects the chest only; by its communicability to pigs, sheep, pigeons, and even horses, which are all immune from lung plague; and by the usual absence of lung lesions of different ages, which are so characteristic of lung plague. The abundance in the blood of the cocco-bacillus with bipolar staining in hæmorrhagic septicæmia is characteristic. Lung plague spreads slowly to exposed cattle, but spares all other domestic animals.

From Rinderpest it is differentiated by the history of its advent, by the presence of the surface œdematous swellings, by the absence of the whitish epithelial concretions on the mouth or vulva, and of the deep dark portwine discolorations of the mucosæ of the mouth, rectum and vulva, and by the fact of its inoculability on domestic animals generally. Rinderpest spreads rapidly to all exposed ruminants, but spares pigs, rabbits, Guinea pigs, horses and birds.

From malignant œdema it differs in its inoculability on the surface in place of subcutaneously only, in the presence of the cocco-bacillus in the blood during life, whereas in malignant œdema the germ is confined to the local lesion, in the absence of crepitation, which may be present in the swelling of œdema, in the greater facility with which cultures can be made of the septicæmic cocco-bacillus and in the absence of gas production in such cultures. The malignant œdema comes from a single accidental deep inoculation from almost any rich soil, and is not a malady spreading widely and generally on given limited damp, rich lands which have become infected. Finally the cocco-bacillus of septicæmia hæmorrhagica is found singly in the blood or exudate, whereas the microbes of malignant œdema may be found in form of sporeless filaments intermingled with the bacilli.

Mortality. The hæmorrhagic septicæmia of cattle cuts off from 50 to 80 per cent. of the animals attacked.

Prevention. The first consideration is to isolate and kill all the affected animals, to destroy the carcasses by burning or boiling and to burn or disinfect all objects that may have become contaminated. The buildings, yards, and fences, must be disinfected, and as the bacillus is very resistant a solution of corrosive sublimate and sodium chloride, a drachm of each to the gallon of water may be freely used after thorough cleansing. Or a whitewash containing ¼ lb. chloride of lime to each gallon may be substituted. Feeding and drinking troughs may be burned. Manure may be freely treated with sulphuric acid. Infected fields should be closed for years and if possible drained.

Immunization of buffalo and sheep has been secured by making cultures of the microbe in free air at 86° to 90° F. and inoculating the animals with the weakened virus, on three successive occasions with intervals of several days. It induces a transient fever, with no serious phenomena (Oreste and Armanni). A second available method is to pass the virus through the system of the pigeon and inoculate with the pigeon’s blood, on three successive occasions, the animals to be protected. It is manifestly impossible to put such immunizing methods in force on wild deer, and for these probably the best course is to drive them from the infected range, to an uninfected one, having retained them for a few days interval in a confined area, to allow of any already infected animals developing the disease. A similar avoidance of waters running from the infected tract is imperative.

Treatment, has been unsuccessful. Friedberger failed with hypodermic injection of carbolic acid, and internal administration of salicylic acid. Gal gave subcutem 5 per cent. solution of creolin, and doses of 1½ oz. of the same agent by the mouth. Five buffaloes out of seventeen recovered. Friedberger suggests deep incisions of the swellings so as to admit the air, and treatment of the wounds with strong antiseptics.

SEPTICÆMIA HÆMORRHAGICA OF THE SHEEP: LOMBRIZ.

Synonyms. Definition. Geographical distribution, Argentina, France, etc. Causes: bacillus; intravenously, etc., youth, verminous affections, low condition. Bacteriology: ovoid bacillus with polar stain, bleached by Gram’s solution, ærobic, nonmotile. Symptoms: Chronic form in summer, diarrhœa, arched back, stiffness, emaciation, flattened wool, segregation, impaired or depraved appetite, shedding wool, anæmic skin, dependent dropsies, sunken eyes, weak small pulse, temperature variable—elevated, nasal and buccal discharge, weakness, paresis, dulness, torpor, lung symptoms, arthritis. Diagnosis: from distomatosis and strongylosis. Acute form with high fever, constitutional disorder, colics, diarrhœa, death in 24 to 36 hours, subacute form. Lesions: black blood, congestions, and general petechiæ. Lungs, liver, kidneys and spleen, congested, swollen. Subacute cases have lighter blood, and lesions. Chronic cases anæmic, blood diffluent, lymph glands enlarged, congested; connective tissues and serous cavities dropsical, gastric, intestinal and hepatic worms, spleen shrunken. Mortality: great in acute, less in chronic. Prevention: segregation, exclusion of all sheep from unknown or suspected flocks, antiseptic dip and quarantine for new purchases, expose a few as a test; cleanliness, disinfectants, avoid watershed from infected lands, wide range, outdoor life, generous diet, remove weak, emaciated, anæmic. Immunization. Treatment.

Synonyms. Pasteurellosis Ovina. Infectious Pneumo-Enteritis.

Definition. An infectious febrile affection of the sheep, chronic or acute, characterized by dulness, stiffness, or paresis, anorexia, thirst, disorder of the breathing and digestive organs, black diffluent blood, petechiæ, reddish effusions in the serosæ or connective tissue, and congestive or inflammatory lesions of the lungs, liver, kidneys and intestines. The presence of a cocco-bacillus (diplococcus, strepto-cocco-bacillus, pasteurellosa) in the lesions is especially characteristic.

Geographical Distribution. Though Lignieres first demonstrated this as a bacteridian disease in the Argentine Republic, he was, after his return, able to identify the same affection in the flocks of almost every department of France, in newly imported English Lincolns and German Merinos, so that there can be little doubt that the malady exists in all or nearly all countries engaged in sheep husbandry, though it has been usually attributed to parasitisms of the lungs, liver or alimentary canal alone.

Causes. The essential cause is manifestly the bacillus, which Lignieres has isolated, cultivated in vitro, and successfully inoculated intravenously in the sheep, which he also infected by feeding the pure cultures. Intravenously it proved fatal to Guinea pig, rabbit, pigeon, chicken, rat, mouse, horse, ass and ox. Yet many other accessory causes must be admitted as operating in different cases.

Youth shows the greatest susceptibility whether the victim be mammal or bird. So marked is this influence that the principle sufferers are lambs just weaned or yearlings. Yet mature animals, that are debilitated from any cause, also fall victims. The measure of immunity usually noticed in mature sheep may well be attributed to a previous mild and non-fatal attack of the bacillus.

Verminous affections are undoubtedly predisposing causes, hence, the common practice of attributing the malady to the worms alone. This again in part explains the susceptibility of the young which so often harbor worms to a dangerous extent. It seems to matter less what worms are present than, that they are in sufficient numbers to greatly deteriorate the health. It is noticeable, however, that those worms that make breaches in the mucosæ, have been noted as infesting the victims of this malady. In the stomach worms sent from Argentina, Railliet identified Strongylus Contortus, S. circumcentus, and S. instabilis and in the duodenum S. filicollis and S. Curticei. These, like the distomata often found in the liver, are blood suckers and not only render the animal anæmic, but make numerous perforations to act as infection-atria. The various lung worms, encysting themselves in the air sacs and determining local congestions may act in the same way, opening channels for the entrance of the microbe.

Low condition or a low tone of health from any cause predisposes. Old, worn out animals, ewes in lamb, or those just lambed, sheep that have been shut up and denied proper exercise in winter, those on poor feeding and perhaps nursing twins, those that have suffered from any debilitating disease of any kind are especially obnoxious to a dangerous attack.

Microbiology. The microbe, which Lignieres found in the pulmonary lesions, is one of the colon group of pathogenic bacteria that have been classed together as pasteurella. It usually appears as a very minute ovoid bacillus which stains promptly and deeply at the poles in fuchsine or gentian violet, leaving a clear median part, so that it seems a diplococcus. It bleaches readily in Gram’s solution. Its form varies in different culture media sometimes showing long bacilli, and sometimes streptococco-bacilli, but the usual and characteristic appearance is that of a cocco-bacillus, and to this it constantly returns. The microbe is ærobic and nonmotile (the slow zig-zag motion sometimes seen does not seem to be automatic). In peptonised bouillon it produces opacity in 18 hours, or in simple bouillon in 24 to 48 hours, the best temperature being 100° F. Gelatine plate cultures are slow because of the compulsory low temperature, yet in 36 to 48 hours it forms pale blue, translucent, round colonies the size of a pin head. It never liquefies. In coagulated blood serum it forms only a thin transparent pellicle hardly visible, and there is no growth on potato.

Symptoms: Chronic Form. In Argentina, Lignieres observed the disease especially during the hot summer months (December to May), and after weaning in the lambs. This may be from the marked change of food, from the greater activity of microbian life at this season, from the exhausting effect of the heat, or from a combination of two or more of these conditions. It appears alike in the sheepfold, and on the open prairie. In considerable flocks the symptoms may be at first overlooked, so that the death of several sheep may be the first thing to draw attention. Then a certain number are found to scour, arch the back, walk stiffly, lose condition, and have the wool flattened and devoid of yolk (clapped wool). The sheep may be dull, lagging behind its fellows, or lying apart by itself, ruminating infrequently and for shorter periods than natural, and there may be inappetence, or depraved appetite (eating earth), though some eat well to the end. Irregular and at intervals capricious appetite is a frequent condition. When caught and examined, the wool is easily torn out, the muscles are soft and wasted, (the leg muscles may have practically disappeared), the bones stand out at all points, the skin is pale, thin, bloodless and devoid of its subcutaneous fat, (paper skin), there may be œdemas along the ventral aspect of the body, pitting on pressure, and between the branches of the lower jaw (poked), the eyes are sunken, the conjunctiva may be puffy and œdematous, but like the muzzle and mouth they are pale and anæmic and the pulse is small, though the excitement may have roused cardiac palpitations. The temperature varies from time to time often reaching 105° or 106° F. There is liable to be a muco-purulent discharge from nose and mouth especially noticeable during drinking. As the disease advances the subject becomes weak, paretic, dull and stupid, it remains down without interest enough to seek food, though still eating if it is brought to it. The head is usually rested on the flank, and the animal often lies so for days in a state of semi-stupor without disposition or ability to rise, paretic or paraplegic. Auscultation may sometimes detect a mucous râle or crepitus, and percussion a flatness of sound over some part of the lung. Chronic arthritis is an occasional symptom.

Diagnosis. The symptoms closely resemble those of distomatosis or strongylosis, and the disease is often complicated with one or more of these, so that it may become difficult to judge how much is due to the microbian infection and how much to the helminthiasis. The presence, continuously or intermittently, of the hyperthermia is almost pathognomonic of the operation of the microbe.

Acute Form. This has been particularly observed in the ewe just after lambing, when the system is especially susceptible to microbian invasion, and little able to cope with it. There are hot ears, nose and feet, temperature of 104° to 106° F., accelerated pulse and breathing, anorexia, ardent thirst, deeply congested mucosæ, colicy pains, pawing the ground, frothy or bloody diarrhœa, arched back, pendent head, ears and eyelids, muscular trembling, albuminous urine, plaintive cries, dark red vaginal discharge, muco-purulent or glairy nasal discharge, and death in 24 to 36 hours. Such animals may be in fair condition or even fat, no time having been allowed for emaciation.

In other cases death may be delayed for three or four weeks, with the same general symptoms, only less marked. In such cases, pregnant ewes are likely to abort, and the lambs are born dead, or prove weak and listless, and die when a few days old. Some have too little energy to suck; others suck heartily but perish all the same on the second or third day, after diarrhœa, thirst, hyperthermia, prostration, and stupor.

Lesions. These vary according to the type. In the rapidly fatal cases there is dark colored blood, with congestion of the serous and mucous membranes, which, together with the skin and often the solid tissues, are covered with petechiæ, and even circumscribed hæmorrhages. The lungs, liver, kidneys, spleen, and many of the lymph glands are congested and swollen, seeming at times of a black hue as if blood-saturated. The lesions, indeed, indicate an acute septicæmia.

In cases that have survived three or four weeks, the morbid changes are slighter, the blood is brighter in tint, and the congestions less deep in color, ecchymoses may be especially confined to the heart, abomasum and small intestines, which may also show hæmorrhages. Enlargement and congestion of the lymph glands are the rule, while pulmonary consolidation and gastro-intestinal mucous inflammations are frequently found. As in the more acute types the urine is albuminous.

In chronic cases the anæmia is prominent. The clot is soft, relatively small, elastic and black, the serum is relatively very abundant and pale. The red globules are greatly reduced in numbers, and there are a number of giant cells which stain deeply as in chlorosis. The lymph glands are usually enlarged, softened and slightly congested but rarely the seat of blood extravasation. The tissues generally are pallid, soft and shrunken. There is a marked absence of subcutaneous and intermuscular fat, while the connective tissue is more or less infiltrated with a transparent, watery lymph. The serous cavities usually contain more than the normal amount of fluid, transparent or straw-colored, and with few globules or granules. Congestions and even shreds of false membrane are sometimes present on the serosa. In some cases the lungs and bronchia are the seat of inflammatory exudates, causing nodular consolidations of from one-half to one inch in diameter. Not unfrequently the lungs show strongylosis as the fourth stomach shows strongylus contortus, the small intestines strongylus filicollis, tæniae (expansa, fimbriata, etc.), the large intestines æsophagostoma Columbiana, and tricocephalus affinis, and the gall ducts distoma hepaticum and distoma lanceolatum. In these chronic cases the spleen is usually shrunken, and the liver firm, sometimes even cirrhotic.