76 
Equine Piroplasmosis 
which usually does not appear to be injured in the process. As 
previously stated, we find that corpuscles containing four parasites are 
liable to “ vanish ” earlier than do others. 
(C) Distribution of the parasites in the body. 
Immediately after the death of the horses (Nos. I and III) smears 
were prepared from the internal organs and stained, and the percentage 
of infected corpuscles and of different types of parasites enumerated. 
The counts, which we need not give here, revealed no more than did 
those made from the peripheral blood during life. The percentage of 
infected corpuscles appeared to be fairly uniform in all the organs 
examined, viz. spleen, liver, kidney, suprarenal glands, lung, heart- 
muscle, brain, and blood taken from the jugular vein and heart, etc., 
gave similar counts to those obtained with peripheral blood. When the 
parasites were classified according to types, the predominant forms were 
small, ranging from 50 to 80 “/o of the total number of parasites observed 
in the organ smears. Judging from the percentage of extracorpuscular 
forms, the breaking down of the infected corpuscles in Horse I took 
place sooner than in Horse III on the approach of death ; the blood 
from the various organs of Horse III contained from 14 to 22 ®/o of the 
parasites free in the plasma, whereas at no time were more than 5®/o of 
tree parasites detected in the peripheral blood of this horse whilst the 
animal was alive. 
Observations on the blood. 
In the case of N. equi Horse III (refer to protocol and chart in the 
Appendix, p. 88), which had been previously infected with P. caballi, 
blood counts showed a fall in the number of red blood corpuscles as the 
disease progressed. When the parasites appeared there were roundly 
nine million red blood corpuscles present per c. mm.; on the 12th day 
they had fallen roundly to seven million, and the fall continued so that 
on the 19th day only three million were present. The haemoglobin 
showed an almost corresponding fall. The leucocytes were markedly 
increased on the two days preceding the day when the horse died. 
Differential leucocyte counts were made on only four days; they 
showed a marked decrease in the number of eosiuophiles. Nucleated 
red blood corpuscles were found on the 17th and 19th day. The blood 
was not studied in Horses I and II. In Horse III there were haemo- 
globinuria and jaundice. 
