192 JOHNE’S DISEASE 
involved. In addition to cattle, sheep, goats, deer, buffalo and possi- 
bly the horse are susceptible. 
History. Johne and Frothingham described a disease in 1895 in 
which the intestinal mucosa contained large numbers of acid-fast 
bacteria. They thought it was a case of tuberculosis in a cow due to 
the avian tubercle bacterium. In 1903 Markus called attention to 
its frequent occurrence in Holland. Since that time it has been 
recognized in Belgium, Switzerland, Denmark and England. <A few 
cases have been observed in this country. Sir John M’Fadyean has 
proposed the name Johne’s disease for this very serious affection. 
It seems to be prevalent in many localities.* 
Etiology. The cause of this disease is an acid-fast bacterium 
(B. paratuberculosis) which is found in large numbers in the affected 
mucosa, and also in the mesenteric and colic lymphatic glands. 
Morphologically it closely resembles the tubercle bacterium. It 
varies in size from 1to 2y, in length and a few are said to attain to 4u. 
It stains uniformly with the acid-fast stains. Occasionally the 
longer forms show alternating stained and unstained segments. 
According to M’Fadyean this organism is not inoculable to either 
guinea pigs or rabbits. It has been cultivated on media containing 
the dead bodies or extracts of a number of other acid-fast bacteria. 
From these cultures it has been grown on media not containing acid- 
fast organisms. 
fe This bacterium apparently does not form a strong cell poison, 
which may account for the absence of necrosis. On the other hand, 
*Stockman in his article on Johne’s disease in sheep refers to a malady of sheep on 
the Eastern border of England and Scotland known locally as “scrapie.” In the 
intestines he found acid-fast bacilli indistinguishable from those of Johne’s disease. 
M’Gowan (Investigation into the disease of sheep called “‘scrapie,”’ 1914) considers the 
all important symptom to be pruritis. He believes it to be the one distinguishing sign 
by which it may be recognized. His conclusions, after a careful investigation, are that 
the cause of ‘‘scrapie” is a heavy infestation of the sheep with a Sarcosporidium. His 
final conclusions are: 
“The sarcocyst is always present in the skeletal muscles of scrapie sheep in large 
numbers; and the more advanced the case the larger is the number of the sarcocyst 
present. 
“Pruritis (or itching), the chief symptom in scrapie, can be reproduced in rabbits 
by the injection into them of sarcosporidial emulsions. 
“Careful clinical examination of typical cases makes it highly probable that the 
paretic phenomena of the disease are due to a primary muscle lesion. 
“There is an absence of any condition post-mortem, except extensive sarcosporidiosis, 
sufficient to or of a nature likely to cause the phenomena observed in the disease. In 
this connection one would specially note Cassirer’s findings in cases of the Traberkrank- 
heit in Germany 
“No single view can explain so well the symptomatology and the epizodtiology, etc. 
of the disease as this.” 
