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.