APOPLECTIFORM SEPTICÆMIA IN CHICKENS.
Streptococcic infection in hens. Most violent in pullets and hens; less so in capons and cockerels. Found dead, or sick 24 hours, ruffled, prostrate, neck limp, head drooped, indisposed or unable to rise, liquid icteric fæces, blood-stained skin of neck and breast, death without agony. Lesions: Soiled anal feathers, plump carcass, skin pallor save neck and breast, extravasation of blood subcutem and intramuscular, mucosæ anæmic, peritoneal engorgement and effusion, enlarged, engorged liver, cell proliferation, degeneration, coagulation necrosis, gall bladder full. Enlarged congested spleen, degeneration. Congested swollen kidneys, epithelial degeneration, casts, streptococcus. Congested, consolidated bronchioles, alveoli, lungs, with microbe. Meningeal congestion, exudate. Bacteriology: Streptococcus, pure cultures in lesions, size, chains, tetrads, staining qualities, culture media, colonies, action on sugars, acid, no gas, on milk no coagulation, on gelatine no liquefaction. History: Stagnant water; no evident source of infection, buzzards, etc. Pathogenesis: Inoculation, intravenous or intramuscular, feeding. On duck, pigeon, rabbits, mice, dogs. Guinea pigs and sheep immune. Immunization by injection of sterilized cultures.
Under this name Norgaard describes a hæmorrhagic streptococcic infection which prevailed in 1901 in a flock of 200 to 250 Plymouth Rocks in Loudon County, Va. Forty birds died within six weeks, and later the mortality reached 200, death often occurring suddenly while feeding, or the birds would drop from their roosts in the night and be found dead in the morning.
Symptoms. In the majority, the pullets which died suddenly, no symptoms whatever were observed, yet a certain number of the capons and cockerels were noticeably ill for 12 to 24 hours. In these the feathers were ruffled, the prostration extreme, the head drooped between the wings, the neck was weak and wobbling (limber neck), the wings and tail drooped, and the animal lay on its breast often unable to rise. Sometimes there was a passage per anum of liquid bile-stained mucus. Close examination of the neck and breast might detect hæmorrhagic discoloration of the skin, though the skin elsewhere was pale and smooth. Death takes place without a struggle.
Lesions. The anal feathers were usually stained, indicating diarrhœa; the picked carcass was plump and fat, with pale, healthy looking skin, except on the neck and breast, where it was discolored by extravasated blood; at such points the connective tissue and muscles were infiltrated with blood in areas of an inch in diameter, more or less, and with irregular outlines. The buccal mucosa was clear, pale and bloodless. The cavity of the body contained an abundance of sero-sanguinolent exudate, and the mesenteric veins were engorged. The liver was greatly enlarged and congested, the greater part of its substance being apparently composed of the distended blood vessels. The hepatic cells were granular and fatty, and if death had been delayed over twenty-four hours their outline became indistinct and the nucleus stained only faintly. In the foci of disease were clumps of round cells and leucocytes in and between the acini, and in still more tardy cases points of coagulation necrosis. The streptococcus was abundant in the necrotic centres, among the clumps of leucocytes, in the parenchyma and capillaries. The gall bladder was usually distended with bile. The spleen had the large size and well developed Malpighian bodies that characterize the well-fed bird, but it showed still greater enlargement, combined with sanguineous congestion and circumscribed blood extravasations. With a hand lens were seen numerous round, semi-transparent points, the size of pin holes, which the microscope revealed to be centres of coagulation necrosis, surrounded by embryonic tissue. The centres consisted of a granular debris with abundance of the streptococcus. The kidneys were congested and swollen, and in cases that had survived two or three days there was granular degeneration of the epithelium of the tubules, and the lumen of the tubes contained casts with leucocytes and streptococci. The organism was also present in the capillaries. The lungs presented areas of congestion and consolidation, exudation into the walls of the bronchioles and the alveoli, and an abundance of streptococci in the lesions. In the cranium were a subdural exudate and meningeal congestion. For examination of the tissues they were hardened in specimens of alcohol of encreasing strengths, embedded in paraffin and stained with carbol fuchsin with a counterstain of methylene blue.
Bacteriology. The streptococcus was found in pure cultures in all the diseased centres except in the intestinal contents. Smear preparations were made from the blood, the abdominal exudate, the intestinal contents, the bone marrow, the cerebral exudate and the sanguineous effusions into the muscles.
The coccus is .6 to .8μ in diameter, in short chains of 2 to 8 cells, or in some media much longer. Involution forms are common, and Norgaard claims to have seen indications of fission in two directions to form tetrads. The organism stains in the usual aniline dyes, as well as by Gram’s and Gram-Weigert’s method. It is nonmotile, ærobic, facultative anærobic, grows in solid and liquid media that is neutral, or slightly acid or alkaline (not if strongly acid), best at 98.6° F., and slower at the room temperature. In alkaline peptonized beef bouillon in 24 hours it forms threads and balls on the sides and bottom of the tube, leaving the liquid clear. On agar there are formed small shining, grayish colonies 1.5 mm. in diameter with brownish centre and bluish periphery. With all the sugars it produces acid, but no gas. It does not coagulate milk. On gelatine colonies are formed in four days, and there is no liquefaction.
History of the Outbreak. The outbreak commenced early in January, without any obvious occasion for the introduction of infection. There had been no chicken disease on the place for 25 years, and no chickens had been purchased except from a neighboring farm where the stock remained healthy. They had been fed on corn meal, wheat bran, wheat tailings and whole corn, together with scorched wheat from a burned barn. The poultry houses were clean and well aired, and after they had been closed there was no abatement of the disease. The water was from a stagnant pool receiving drainage from the stable, but this was no new condition and January is not the driest month with the foulest water. The suggestion may be hazarded that the infection may have been introduced by the usual infection bearer, the buzzard, or by some other wild bird, or mammal.
Pathogenesis. Among the chickens the most rapid and fatal cases were in pullets, then among the laying hens, while the capons and cockerels were less severely affected, and some survived from three to seven days.
Those inoculated intravenously as a rule sickened on the second or third day with a temperature of 110.7° F., and were found dead the following morning.
Some took injections of .25 to 1cc. in the pectoral muscles with impunity.
Chickens that had fasted 24 hours, took each daily for 3 days, a few cubes of bread soaked in a fresh bouillon culture. Death followed in four out of six, in from four to thirteen days from the beginning of the experiment. The birds gradually became listless, refused to eat, and remained quiet in a corner of the cage, with closed eyes and head drooping until it rested on the ground. Diarrhœa was frequent but not invariably present.
Chickens fed on the chopped up viscera of rabbits that had died of the disease perished in 3 to 10 days.
A white duck inoculated intravenously with .5cc. of peptonized beef bouillon culture, took ill on the 8th day, and died on the 12th. There was loss of coördination and use of the wings, temperature 109° F., and necropsy showed valvular endocarditis containing the streptococcus. A second duck sickened on the 11th day, but recovered after three days’ illness. Killed on 21st day, all cultures from heart, spleen and kidney remained sterile. Subcutaneous, intramuscular and feeding experiments failed to produce the disease in ducks.
A pigeon injected with .5cc. bouillon culture intravenously died on the fourth day with the internal lesions of chickens, and blood extravasations on head and neck. Intra-muscular injections and feeding experiments were fruitless.
In rabbits, intravenous injections of 1 to 1.5cc. led in 24 hours, to temperature of 105.3° F., without impairment of appetite, or other marked sign of illness, and as a rule the subject is found dead next morning. Intra-abdominal and intrapleural injections kill in two to four days, and subcutaneous ones in three days. In addition to the lesions found in chickens, there is often bloody urine, a sanguineous lymph on and beneath the cerebral meninges and in the fourth ventricle, and deep congestion of the cancellated tissue of the vertebræ. Streptococci are abundant in the lesions.
In mice intraabdominal injection of .01cc. killed in 48 hours, and subcutaneous injections in 2 to 5 days. The lesions were like those seen in birds, and streptococci were abundant.
In dogs after intravenous injection there was hyperthermia (103.6° and 104.1° F.) and lameness of the right fore shoulder joint, followed in 5 to 8 days by recovery. Feeding on the viscera of the diseased chickens, was followed by anorexia, and vomiting only.
Guinea pigs and sheep proved refractory.
Immunization. The injection into the wing vein of .5 to 2.5cc. of bouillon culture, sterilized by heat proved protective to the chickens against inoculations of the virus while the check animals invariably died.