MENINGITIS IN HORSES 461 
different results have been obtained. The cause was attributed, at 
least in many instances, to decomposed fungus infested food and 
consequently “forage poisoning” became a popular name for these 
cases. There is a large literature on the subject. The affection in 
Germany known as “Borna Sickness”’ has been more carefully studied 
and its lesions described. They are thought by Friedberger and 
Fréhner to be different from those of cerebro-spinal meningitis. 
Johne and Ostertag held the same opinion. Cadéac does not differen- 
tiate them. In this country there have been serious outbreaks in 
which the diagnosis has been in doubt. The work of Jcest and Dengen 
has clearly defined the Borna disease. Udall considers the disease 
that occurred in Kansas and Nebraska in 1912, the outbreak of 
“enzootic cerebro-spinal meningitis” described by Williams in Idaho, 
by Milks in Louisiana and by Jcest and Schmidt in Saxony to be the 
same. He does not think they are identical with the forage poisoning 
described by Pearson and the anatomical changes are different from 
those found by McCarthy and Ravenel and designated acute epizo- 
otic leucoencephalitis. There is great need for further investigation 
into the nature of this class of disorders. 
Geographical distribution. This disease seems to be wide-spread. 
The incomplete differentiation of “forage disorders” from the specific 
cerebro-spinal meningitis leaves the nature of the disease in many 
outbreaks still in doubt. 
Etiology. The cause has been attributed to a great variety of 
agents, such as several species of bacteria, fermented food, forage 
laden with fungi or toxic moulds, various insanitary conditions and 
other ill-defined agencies. It seems to be true that in most outbreaks 
all of the animals that suffer have had at least some one thing in 
common either in surroundings, food or management. The bac- 
teriological examinations have not resulted in finding a specific agent. 
Micrococci and various bacilli have been isolated from the infected 
animal. The writer made a careful examination of animals in two 
outbreaks. In one of them all inoculated media and histological 
examinations gave negative results, in the other pure cultures of a 
colon bacillus were obtained from the brain. Jcest found intranuclear 
bodies in the large cells of the hippocampus and of the ophthalmic 
tract. They resemble Negri bodies in rabies, but they are located 
within the nucleus while Negri bodies are extranuclear. Jcest 
believes the virus gains entrance to the brain through the lymph 
vessels of the nasal mucous membranes. 
