246 DISEASES OF DOMESTICATED BIRDS 
Prevention. Individual isolation of birds is the most effective 
means of preventing the spread of the infection. General disinfec- 
tion is indicated. 
OSTEO ARTHRITIS IN YOUNG GEESE AND DUCKS 
Synonyms. Ostéo arthrite aigue des jeunes oies, French; osteo- 
arthritis bei jungen Gansen und Enten, German. 
Characterization. The affection consists principally of a serous 
or sero-fibrinous arthritis, hemorrhagic inflammation of the bone 
marrow and intestinal catarrh. 
Geographical distribution. Outbreaks have been reported in 
France, Germany and in the latter country among birds that had 
recently been imported from Russia. It is reported as generally 
‘distributed in Germany. 
History. The disease was first described by Lucet in France in 
1892, by Freese in Germany in 1903, and by Hasenkamp and 
Sachweh in the same country in 1914. 
Etiology. Pus from all joints examined bacteriologically yields 
pure cultures of Staphylococcus pyogenes aureus which, however, 
forms but little pigment. The organism is recognized microscopi- 
cally in pus in great numbers and a few are observed in smears from 
heart blood. 
Pathogenicity. Only young geese and ducks are susceptible, of 
which 90 per cent become affected. Old geese and ducks, hens and 
pigeons are immune. Hasenkamp and Sachweh report one instance 
of finding a dead hen in an establishment where ducks were infected, 
but made no bacteriological examination. 
The hen, pigeon and rabbit injected subcutaneously with blood 
of an infected bird, remain healthy, The hen and pigeon likewise 
are not affected by subcutaneous injection of pus from the joint of 
an affected bird. Hasenkamp and Sachweh have infected hens and 
pigeons by intravenous inoculation. 
The disease is transmitted to young ducks by intravenous inocula- 
tion with culture of S. pyogenes aureus. Subcutaneous inoculation 
or ingestion have failed to induce infection. 
Mortality. Léffer observed an outbreak of the disease among 
346 geese, of which 43 were old, and 313 young ones. Of the 346 
geese, 191 became sick. Of these latter 5 were old and 186 were 
young. One old one and 159 young died. The mortality among 
the young ones was 85.5 while that of the old ones was 20 per cent. 
