Lesions. These are like those of surra. Enlargement of the lymph glands, spleen and liver, firmness, friability and dark color of the spleen; effusions, petechiæ, and even hæmorrhages of the serosæ, lungs and stomach, and great atrophy of the muscles and adipose tissue are prominent features. The liver is always fatty in rabbits. In the shafts of the long bones, the fat is replaced by red marrow. The bone marrow is sometimes red, at others pale.
The trypanosomata in the blood vary greatly. In infected rats and mice they appear 3 or 4 days after inoculation, are almost constantly present thereafter, and as a rule, encrease steadily up to 2,000,000 or 3,000,000 per c.m. In dogs they appear in 4 to 6 days, in cats in 5, in Guinea pigs in 5 to 7, and in horses in 7 days. In rabbits there were found 60,000 per c.m., in dogs 100,000 to 300,000, and in Guinea pigs 200,000 to 500,000. In one Guinea pig they did not appear until 6 weeks after inoculation and then rapidly encreased to a fatal termination. More commonly a few can be found about a week after inoculation, and then they disappear for a variable period. They have been found in the bone marrow when they could not be recognized in the blood. Again, after subcutaneous flank inoculation in the rat, they were found in the corresponding inguinal glands 1 to 3 days before they could be detected in the blood. After death they are found most abundantly in the bone marrow and spleen, but they have not been found in the intestinal contents nor urine except in the case of hæmorrhages or local sores.
No soluble toxin appears to be formed, and no immunization is effected by the serum. Blood serum kept several days until the infusoria had died and then passed through a Berkefeld filter had no apparent effect on the animal economy even in large doses. Blood heated to 122° F. was equally harmless. The same is true of extracts of organs and of bile from infected animals.
Attempts to secure immunity by injecting the blood serum of affected animals, after it had been sterilized by heat, filtration, or standing one week in vitro proved of absolutely no effect. The blood of the fœtus almost at full term proved valueless, and the young born of infected mothers proved fully susceptible when inoculated. The serum of the Guinea-pig, which is naturally somewhat resistant, proved no protection to other animals. Bile mixed with infecting blood in vitro, kills the trypanosoma, but such blood has no protective effect on animals. Sewer rats and white rats inoculated and re-inoculated with the common rat trypanosoma (T. Lewisi) until immune from that organism, show a full susceptibility to the trypanosoma of nagana.
Flesh feeding and vegetable feeding have made no difference in the susceptibility in the case of rats. Feeding with the hæmatozoa has produced no immunity.
It is evident that prevention must follow the same lines as in Surra, due consideration being had of the greater number of genera susceptible.
LUNG PLAGUE OF CATTLE.
Synonyms. Definition: infectious, cattle fever, with long incubation, insidious onset, excessive pulmonary exudation, infarctions and sequestra. History: ancient, modern; England, Norway, Sweden, Denmark, United States,—its extinction in 1887 to 1892—Massachusetts, New Jersey, S. Africa, Australia, Tasmania, New Zealand. Causes: contagion only. Bacteriology: Nocard’s organism cultivated in collodion capsules in vivo, as actively motile refrangent points, morphology uncertain. Modes of transmission, exhalations from sick inhaled by susceptible, ingestion of infected food, pastures, watering troughs, ponds, commingling of herds, attendants, dealers, stables, manure, unrestricted commerce, convalescent cattle, breed, hot seasons. Lesions: profuse exudation in lymph networks of lungs, marbling, parenchymatous cell proliferation, compression and gangrene of lobulets, thrombi, sequestra, infarction, fibroid sac, or stalactite-like fibroid peribronchial formations, hepatization, pleural effusions and false membranes, pericardial, bronchial, lymph glands congested. Incubation: 6 to 30 days, protracted cases, bearing on quarantine. Symptoms: conditions affecting gravity, breed, excitement, heat, chill, susceptibility, usually insidious, infrequent cough, roused by cold water, dusty food, exertion, etc., hurried breathing when driven, slight auscultation râles, hyperthermia (103° to 108° F.), dulness, anorexia, suppression of milk, stiffness, no pandiculation, troubled breathing, auscultation, and percussion signs of extensive consolidation, tenderness of chest walls, in bad cases stands obstinately, head extended, mouth open, tongue protruded, grunts with expiration, heavy breath, nostrils dilated, nasal and buccal discharge, rapid emaciation, fœtid diarrhœa, erect hair, pale, scurfy, adherent skin, varied chest râles, abortion. Mild in winter, severe in summer. Loss of one-third or one-half weight in one week. Chronic cases, fibroid and necrotic changes, sequestra. Diagnosis: Anamnesis, inoculation: from tuberculosis by high fever, rapid, extensive infiltration, early succession of new cases, failure to react under tuberculin, absence of tubercles; from bronchitis and pulmonary strongylosis, by the succession of cases in place of many at once, the extensive exudation, the evident cause (exposure or infected place), and by the lesions; from fibrinous pneumonia, by absence of climatic cause, the more extensive consolidation, more troubled breathing, and coexistence of old and recent lesions; from infectious pneumonia by the greater area consolidated, more exalted hyperthermia, more marked dyspnœa, the absence of white points of alveolar cell proliferation, and by the old and recent lesions; from septicæmia hæmorrhagica, by its occurrence at all seasons, on all soils, by the absence of sanguineous swellings at other parts, by the absence of cocco-bacillus from the exudate, and by its non-inoculability on sheep, horses, pigs and rodents; from needle in pericardium, by its epizoötic prevalence, fever, and the absence of preliminary gastric and later cardiac, morbid phenomena; from emphysema by the fever, absence of drumlike tympany, and presence of consolidation; from aspergillosis of the lung by the fever, more rapid progress and extended consolidation, by the harmlessness to birds, by the absence of aspergillus from expectoration and lung; from insolation by the absence of the causes of heat stroke, of the implication at once of a number of exposed animals, of the excessive hyperthermia, the brain symptoms and sudden deaths. Treatment: a poor economy, to be punished when extinction is attempted. Prevention: importation under three months quarantine, surveillance of three months more in case of single animals; applied to lung plague countries and those adjoining; disinfect cars and boats that have been used in lung plague country; exclude hay and fodder from lung plague country; also litter, bags, head ropes, horns, hoofs, hides, hair. To extirpate: stop all ingress of possibly infected cattle, stop movement of cattle, prohibit common or unfenced pasturage, kill without indemnity in case of violation, record all cattle, make necropsy of all dead, kill and pay for all infected herds, disinfect all infected premises and things, use horses in removing and plowing under manure. Unaided owner may: breed all his stock, in buying bull quarantine him, allow no intercourse between his herd and others, get new cattle from herds only that have had no illness nor losses for a year, and no exposure, and bring by thoroughly safe route, in disinfected cars or boats, then quarantine, under special attendants. Immunization; by a first attack, inoculation in tail, intravenous, of sterilized exudate. Conditions permitting and forbidding immunization.
Synonyms. Bovine Pleuro-Pneumonia, Contagious Pleuro-Pneumonia, Peripneumonie (Fr.), Lungenseuche Vieseuche (Ger.), Pneumosarcia, Peripneumonia Exudativa, Epizoötic Pleuro-Pneumonia, Pulmonary Murrain, Slijmlongziekte (Dutch), Pulmonea dei Bovina (Ital.), Phush phush pirdaho, Pheepree (Bengalee).
Definition. An infectious febrile disease, occurring casually in cattle only, so far as known, and characterized by a prolonged incubation (10 to 90 days), a tardy insidious onset, inflammation of the bronchia, lungs and pleuræ, a profuse exudation into the interlobular connective tissue and chest, a very extensive area of consolidation, pulmonary infarction, and sequestra.