Gk H. F. Nuttall and S. Hadwen 
265 
Summary and Conclusions. 
1. Trypanblau promises to be an efficient remedy for bovine 
piroplasmosis, since it exerts a direct and obvious effect upon the 
parasites. 
2. The effect of the drug upon Piroplasma bovis is similar to that 
which it produces upon the canine parasite. The dividing forms are 
the first to disappear, and after a few hours the pyriform parasites also 
disappear from the peripheral circulation; the parasites which are 
detected in the blood after a few hours appear degenerated and rounded 
or irregular; within nine to 45 hours or less all the parasites have 
disappeared from the blood. 
3. As in canine piroplasmosis the disappearance of the parasites 
from the blood may be temporary. The parasites also disappear and 
reappear in small numbers (after two to 11 days) in animals undergoing 
natural recovery. In three treated animals the parasites reappeared in 
exceedingly small numbers after five to six days; in two they had not 
reappeared after 16 and 18 days respectively. The animals show no 
symptoms and progress towards recovery. 
4. It remains to be determined (1) how long the blood of treated 
cows may contain parasites after the apparent recovery, (2) if the 
parasites in such recovered animals are altered in virulence, (3) if the 
parasites are capable of infecting ticks. 
5. The experiments were conducted on nine cows, of which four 
served as controls and five were treated with trypanblau. Of the 
controls two suffered from haemoglobinuria, and one of these died of 
piroplasmosis; the two other controls had no haemoglobinuria and were 
very mild cases. All of the treated cows had haemoglobinuria and 
recovered. In four of the treated cows haemoglobinuria occurred before 
treatment began. 
6. As might be expected, the drug exerts a more rapid effect when 
injected intravenously. The parasites disappear more slowly after 
subcutaneous injection of the drug. (Judging from our recent experi¬ 
ments on dogs, the giving of the drug per os promises to be without 
effect. See This Journal, p. 231.) 
