INFECTIOUS DISEASES OF GEESE AND DUCKS 249 
a pure serous fluid or a sero-fibrinous exudate. The fibrin occurs 
mostly as a yellowish, transparent layer on the joint cartilages and 
on the inner wall of the joint capsule. 
The exudate is present in various amounts. The synovial mem- 
brane of the joint capsule is swollen and reddened in the acute cases. 
The bone marrow is very shiny, dark red in color and the consist- 
ency is strikingly soft, often fluid. : 
In the chronic form the joint cartilage is involved in spots and is 
easily lifted from the tissues beneath. Under these spots, the bone 
has a porous, rough consistency. In the epiphyses of the bone are 
noted cavities of various sizes which are filled with dry, crumbly, 
grayish yellow masses. These when rubbed between the fingers feel 
granular and are regarded as bone pus. Freese observes that pus 
in birds has this consistency instead of the creamy-like character 
of that occurring in mammals. In other epiphyses there are holes 
in the joint cartilage which communicate directly from the joint to 
the cavities in the bone described above. In such cases the joints 
contain more or less of the bone pus. The bone of the altered epi- 
physes is covered on the outer surface with a cartilage-like deposit, 
which is easily overlooked. 
Prevention. Prophylactic measures should include separation 
of the sound birds from infected ones, disinfection of the quarters, 
proper disposal of the dead and of the manure. 
Treatment. The advisability of local treatment with counter 
irritants and disinfection might be considered. 
SEPTICEMIA OF DUCKS 
Lisi has described a fatal septicemia of ducks in which all birds 
exposed to the infection succumbed. 
Etiology. The causative organism is present in the various 
exudates, organs and in small numbers in the blood. It is somewhat 
larger than that of fowl cholera. The organism grows on gelatin, 
causing slow liquefaction and forms a brown colored layer on potato. 
Pathogenicity. Inoculation of ducks with culture causes death 
in ten or twelve hours. Rabbits and guinea pigs succumb in three 
days. The fowl is refractory. The white rat is somewhat suscept- 
ible and an area of caseous infiltration forms at the point of inocula- 
tion. 
Symptoms. The advent of symptoms is abrupt, the eyes are 
closed and lachrymating. The bird appears depressed and remains 
