MUKTESAR, FOR THE YEAR ENDING THE 31ST MARCH, 1925
47
(c) Normal, unfiltered muscle juice. One pony foal, died (in 4 days); one donkey
foal recovered.
(d) Normal, filtered muscle juice. One pony foal, died (in 4 days); one donkey
foal, died (in 2 days).
(e) Controls, untreated. Two pony foals, both died (in 5 and 12 days); two donkey
foals, both died (in 3 and 6 days).
Test No. 2 (20th December 1924). Vaccinated as above. Tested by inoculation
intramuscularly of centrifuged deposit of virulent muscle juice. Results with donkeys
were:—
(a) Strangles unfiltered aggressin. One donkey foal, lived.
(b) Strangles filtered aggressin. One donkey foal, lived.
(c) Controls, untreated. Two donkey foals, both died (in 11 and 21 days).
Test No. 3 (9th January 1925). Vaccinated as above. Tested by intramuscular
inoculation of emulsion of deposit of live streptococci grown in horse serum broth, and
comprising in equal parts the three strains with which the aggressin was originally manu-
factured. Results with donkeys were:—
(a) Strangles unfiltered aggressin. Two donkeys, lived.
(b) Strangles filtered aggressin. One donkey, lived.
(c) Normal, unfiltered muscle juice. One donkey, lived. *
(d) Normal filtered muscle juice. One donkey, died (in 27 days).
(e) Controls, untreated. Two donkeys, both died (in 9 and 12 days).
It seemed in any event from the above results that inoculation with the " aggressin "
ought to be capable of mitigating the incidence of strangles if the real origin of the affec-
tion is streptococcic invasion.
Prior to the onset of the strangles season 1924-25 at the Remount Depôts, this form
of vaccine was therefore issued to be applied to the remounts admitted, on the condition
that one-third of each batch received should remain untreated, to serve as " controls."'
The dose of aggressin injected was 20 c. c. (of the infected muscle juice diluted with equal
parts of sterile salt solution prior to filtration).
The results, expressed crudely, are as follows :—
Depôt
Mona
Sargodba .
Vaccinated
Controls .
Vaccinated
Controls
Total
number
292
144
300
150
Remained
free
82
(28.1 %).
41
(28.5 %).
138
(46.0 %).
64
(42.7 %).
Became
affected
210
(71.9 %).
103
(71.5 %).
162
(54.0 %).
86
(57.3 %).
SEVERITY OF AFFECTION
Mild,
recovered
162
(55.5 %).
78
(54.2 %).
Severe,
recovered
29
(9.9 %)
15
(10.4 %).
145 (48.3 % ).
81( 54.0 %) .
Died
19
(6.5 %).
10
(6.9 %).
17
(5.7 %).
5
(3.3 %).
At Mona, strangles broke out in the Depôt while the inoculations were in progress,
but examination of the detailed histories received indicates that the interval between
the date of inoculation and the first appearance of symptoms in nearly all the affected
treated animals was so long that it is hardly likely they were exposed to infection before
the vaccination process had time to become effective, if it was capable of setting up any
appreciable immunity. At Sargodha, inoculations were discontinued after the appear-
ance of strangles in the Depôt. When analysed in any manner, the records indicate
that no appreciable protection was conferred by the procedure adopted.
* It seems from these tests that the animals inoculated with the normal muscle
juice also developed an appreciable degree of immunity; it is not unlikely that this was
due to the formation of abscesses locally after the injection of the juice from which Str.
fæcalis was isolated.