304 SPIROCHAETOSIS IN FOWLS 
spirochete has been assigned different names but whether they are 
different species is not clearly determined. It is possible they are 
identical or varieties of the same species. 
Bevan has described a serious disease of chickens in Southern 
Rhodesia due to a spirochete. He has associated it with the common 
fowl tick, Argas persicus. Lounsbury maintained that the fowls 
died “entirely from the loss of blood and the inflammation produced 
by the excessive parasitism.” Blanchard demonstrated that Spiro- 
chaeta gallinarum is transmitted by the bite of an argas. In Rhodesia 
the disease is most prevalent during the spring months, that is, when 
the first rains set in. Ordinarily the fowls that apparently are healthy 
at night are found dead in the morning. There are chronic cases in 
which the disease manifests itself by ruffled feathers and lessened 
power of the use of their limbs. There is intense thirst and they drink 
large quantities of water. There is diarrhea and sometimes the fowl 
will eat almost till the time of death. The essential lesion is anemia. 
At the point where the tick”attached itself there may be a small sub- 
cutaneous hemorrhage. 
Geographical distribution. Spirochaetosis of fowls is, as stated 
above, widely distributed. It is possible that it exists in the United 
States to a much greater extent than has heretofore been supposed. 
Etiology. Spirochetosis in fowls as originally described is caused 
by Sp. gallinarum. According to Jowett it is found free in the blood 
of the fowl naturally infected and also has rounded bodies in the 
interior of the erythrocytes. The free spirochete is an extremely thin, 
thread-like, spirally formed organism. It is of uniform thickness 
except at the extremities, which are tapered. In the fresh blood they 
are actively motile. In stained preparations they are found to vary 
in size, measuring from 8to10v in length. Occasionally much longer 
individuals are observed. Frequently two spirochetes are joined end 
toend. They are regularly formed spirals but they may be looped in 
the figure of a pattern. The intra-corpuscular bodies may be found 
before or after the free spirochetes or they may coexist with them. 
They are bodies generally round or spherical in form and invariably 
situated in the extra-nuclear portion of the erythrocyte. Jowett 
found they were more frequently located at the end of the carpus than 
in any other place. They are sometimes situated close to the edge of 
the nucleus and at others close to the periphery of the cell. In size 
these bodies vary from one to four microns. Dodd did not find the 
