220 
Immunity in Canine Piroplasmosis 
Nine days after the last injection the dog received 5 c.c. of virulent blood. 
Result: Parasites appeared in the dog’s blood on the 6th day after inoculation and the 
dog died two days later (8th day after inoculation) of piroplasmosis. The dog had haemo- 
globinuria and there were many parasites in its blood, 29 °/ 0 of the corpuscles being 
infected. The types of parasites encountered in the blood on the day when the dog died 
were as follows : 40 % (0), 52 °/ 0 (PP), 3 °/ n (00), 3 % (PPPP), 2 °/ 0 (D) K 
1 The signs used in this paper are similar to those used in the paper by Nuttall and 
Hadwen (1909, p. 162, q.v.). 
Dog 4. 
(Adult Terrier) was treated like Dog 3 
and at 
the same 
time. 
The 
dog received 6 in- 
jections of blood prior to inoculation. 
Doses of blood in c.c. = 
10 
9 20 
20 
10 
20 = Total 89 c.c. 
Number of days the blood had been in vitro 
8 
10 9 
12 
8 
10 
Intervals between injections, in days ... 
2 
11 2 
3 
2 
(15. iv. 09) 
Day 
1 Nine days after the last injection the dog received 5 c.c. of virulent blood containing many 
parasites. 
Percentages of 
Temp. Infected,--'■-. 
"F. r.b.e. P D O PP 00 DD PPO P 4 P 6 P s 
6 
103 0 
Parasites appeared in dog's blood 
+ 
7 
104-6 
25 infected r.b.e. at film-edge 
+ 
. 
• 
60 
36 
• 
. 4 
8 
106-0 
a.m. Treatment: 6 c.c. of 1 °/ 0 
methylene blue (exerted no visible 
effect on parasites) ... 
5 
2 
. 
49 
42 
3 
• 4 
p.m. 
- 
• 
1 
48 
44 
• 
• • 7 
9 
105-0 
14 
2 
• 
45 
48 
1 
4 
10 
104-2 
Dog very weak; haemoglobinuria 
5 
1 
1 
47 
50 
• 
1 
11 
103-8 
Distinct anaemia 
2 
4 
• 
50 
42 
• 
4 
12 
101-0 
Few parasites found ... 
+ 
• 
. 
+ 
+ 
• 
. 
13 
101-2 
Dog weak, anaemic. (No less than 
|Th of all parasites seen were free 
pyriforms, many corpuscles break¬ 
ing up) ... 
0-8 
28 
38 
26 
8 
14 
103-4 
Dog very weak and anaemic. Only 
4 infected r.b.e. found after long 
search: 2 (O), 1 (PP), 1 (PPPP). 
Occasional bacilli in film 
+ 
+ 
+ 
• • + 
15 
104-3 
Condition as on previous day; no 
infected r.b.e. found 
• 
• 
• 
• 
• 
• 
. 
16 
103-5 
Dog exceedingly weak, gait totter- 
ing, 4 infected r.b.e. found, 3 (PP), 
1 (PPPP) 
+ 
. 
+ 
# 
+ 
17 
102-8 
Condition unchanged, blood watery, 
3 infected r.b.e. found: 3 (OO)... 
+ 
• 
• 
• 
• 
+ 
. 
18 
101-3 
Condition slightly improved. No 
infected r.b.e. 
• 
• 
• 
• 
. 
. 
. 
19 
102-4 
Dog better, feeding, no infected r.b.e. 
20 
104-8 
Dog stronger, 1 infected r.b.e., (O) 
+ 
• ■ 
• 
+ 
• 
• 
. 
