136
Contagious Pleuro-Pneumonia of Goats
The doses were : I/Tr. 1.0 c.c., I/Thor. 2.5 c.c. The dose of 1 c.c. of
the emulsion intra-venously killed its recipient immediately, as did also
the reduced dose of 0.5 c.c. The dose was therefore further reduced and it
was found that no more than 0.3 c.c. could be tolerated. On cutting the
throats of these goats immediately after their death, it was found that the
blood of both was completely coagulated, and their deaths and subsequent
similar deaths were attributable to intra-vascular clotting, as a result of the
inoculation of the lung emulsion.
This intra-vascular clotting is a serious objection to inoculations by
this route of any but small quantities of lung emulsions. Attempts to render
the blood incoagulable by injections of Witte' peptone (0.3 g. per kilo body
weight) were unsuccessful. The goat does not appear to react in the same
manner as the dog. Tentative experiments with a preparation of hirudin
indicated that the coagulative effect of the lung emulsion, at least in
vitro, was much too strong, and the quantity and cost of the hirudin neces-
sary to prevent intra-vascular coagulation would have been prohibitive.
It was ultimately found that the dosage of emulsion could be increased to
1 c.c. or more with comparative safety, by the simple expedient of diluting
freely in saline and injecting very slowly, but different emulsions appear to
vary widely in their activity in this respect.
Results.—The goats were kept under observation for a period of 40 days.
At autopsy, four of those receiving intra-thoracic inoculations were found to
have chronic suppurative foci in the lungs at the seat of inoculation. In
each case staphylococci were isolated. No pulmonary lesions were present
in any of the other animals.
Discussion.—There was nothing in the character of the lesions in either
the donors or experimental subjects to suggest that the specific pneumonia,
as now recognised, was being studied. The lesions in no way resembled the
specific pneumonia, with which, at this time, we were not familiar. That
the lesions in the experimental goats were non-specific and due to a conta-
minated inoculum, there can be little doubt.
Experiment 2.—Transmission from pulmonary lesions by inoculation.
On 8th December 1938, a second consignment of five suspected cases
was received from the Veterinary Investigation Officer. All showed clinical
symptoms of pneumonia with varying degrees of fever. This latter is usual
in goats on arrival, and is largely attributable to the journey in the heat of
the sun.
Two healthy goats from the quarantined stock were immediately placed
in contact in the same loose box (Transmission by contact, Experiment 16).
One of the ' donor ' goats died over-night. The typical pleuro-pneumonia,
as now recognised and described, was found at autopsy.
Scheme of experiment.—Owing to the failure of the first Experiment, the
persistent failure of past work, and the urgent need for effecting transmission
at all costs, it was decided in this experiment to administer the emulsion to
each of the six goats of an experimental group by all indicated and convenient
routes (except the intra-thoracic) namely the intra-venous, intra-tracheal,
intra-muscular, subcutaneous and intra-nasal.
Donor.—The temperatures of all but one of the remainder had returned
to normal on the following day, the 9th of December 1938. This one, No. 13,