INFECTIOUS ANEMIA IN HORSES 457 
sopus hematopota and tabanus) are the transmitters of infectious 
anemia in Japan. 
Modes of infection. The disease can be produced artificially in 
horses by the subcutaneous or intravenous injection of virulent blood, 
that is, the blood of the sick horse. The size of the dose, as pointed 
out by Carré and Vallée, does not seem to make any difference. 
Infection may take place through the digestive tract by contaminated 
litter and forage. It is important to note that animals which are 
Fic. 107. MICROPHOTOGRAPH OF SECTION OF THE RED BONE MARROW OF THE FEMUR OF 
A HORSE, SHOWING THE INCREASED ACTIVITY OF THE CELLS OF THE RED BONE MARROW, 
GIANT CELLS AND CONGESTION (after Udall and Fitch). 
apparently healthy but which have previously been infected may 
become “carriers.” The disease does not seem to be directly com- 
municable from one horse to another. 
Symptoms. In the acute attack there isa high temperature (105° 
to 107° F.), rapid and weak pulse. Stiffness, swaying gait, usually 
behind. Udall and Fitch report soreness about the parotid region. 
Epistaxis is common especially in the later stages. The animals 
lose weight rapidly. There may be diarrhea with blood stained feces. 
