454 INFECTIOUS ANEMIA IN HORSES 
INFECTIOUS ANEMIA IN HORSES 
Synonyms: Equine infectious anemia; anémie épizodtique; 
typho-anémie; equine malaria; river-bottom disease; loin distemper; 
mountain fever; swamp fever. 
Characterization. Infectious anemia is a specific disease of the 
horse and mule due to a filterable virus. It occurs sometimes as an 
acute and at others as a chronic septicemic-like disease with rapid 
loss of flesh and pronounced blood changes. It does not attack other 
species, but according to Carré and Vallée it may be transmitted to 
the ass. 
History. Infectious anemia was first described by Lignée in 1843. 
Its infectious nature was pointed out by Anginiard in 1859. In 1883 
Zschokke reported several cases in Switzerland. Carré and Vallée, 
1904-06, carried on extensive studies of this affection. They estab- 
lished the filterability of the virus and showed that it was present in 
the urine as well as in the blood. Their findings were later confirmed 
by Ostertag, Marek and Hempel working independently. In America 
the disease was probably first mentioned by Torrance in 1882 in the 
province of Manitoba. In 1902 he described it quite fully. Since 
that time Van Es, Kinsley, Francis and Marsteller, Mack, Mohler 
and others have published observations on or experiments with it. 
The Seyderhelm’s in Germany and the Japanese Commission 
appointed in 1909 to study this disease have recently reported their 
findings. 
Geographical distribution. Infectious anemia is apparently a 
wide-spread disease. In France it occurs in many localities but partic- 
ularly in the valley of the Meuse. It has been observed in Bavaria. 
Marek has found it in Hungary in three different counties. It exists 
m Switzerland and probably in Sweden. It seems to be quite wide- 
spread in western Canada. Udall and Fitch have recently reported it 
from northern New York. The disease has been found in Wisconsin, 
South Dakota, Nebraska, Nevada, Kansas and Texas. Two general 
features stand out prominently: First, it is a disease of hot weather, 
and second, it shows a strong predilection for rich damp soils. Dr. 
Law makes the statement that it is because of this latter characteristic 
that the disease has been so often referred to under the name of swamp 
fever. . 
Etiology. The specific cause has not been found. Mack describes 
a small body which he finds inside of the red blood corpuscles. Van Es 
