The _Guinea-pig_ is especially susceptible, and like the rabbit and
mouse may contract the disease by eating the soiled fodder of glandered
horses. It is usually selected for inoculation for diagnostic purposes,
because in the male, the insertion of the virus in the peritoneum
determines a rapid swelling of the testicle and cord, with a glistening,
violet engorgement and tension of the scrotum, suppurative adenitis and
death in three to six days. In other situations the inoculated part
swells rapidly and ulcerates, the adjacent lymph glands become swollen
and tender, similar lesions form in other parts and notably in the nose
which discharges profusely a whitish, sticky fluid, the breathing is
hurried, and emaciation is marked. Death occurs in a few days and
ulcers, and abscesses are found in the lungs and other internal organs,
as well as in the nose. In less susceptible subjects or under smaller
doses of the virus the local swelling and ulceration in the seat of
inoculation are slight, but there persist engorgements of the adjacent
lymph glands, swelling (cording) of the lymph vessels adjacent, and
nodules and abscesses, (cutaneous, subcutaneous, intermuscular,
intravisceral), arthritis, emaciation, dyspnœa and death in two to four
months. In some cases with a very small dose of the poison, there is no
local swelling, and no generalization nor subsequent manifestation of
the disease.
In the _rabbit_ the lesions are less certain and often less marked.
There is sometimes no swelling in the seat of inoculation, in the
neighboring lymph glands, nor elsewhere, and the rodent might have been
supposed to have escaped, only that successful inoculation of the ass
may be made from the tissues inoculated (Galtier). In such a case a
certain immunity of the rabbit must be inferred. In less resistant
rabbits, or with a larger dose, an ulcerous swelling forms in the seat
of inoculation, the adjacent lymph glands become engorged or even
purulent, corded lymphatics intervene, and nodules and caseous
degenerations appear in the lungs, nose, spleen, liver, and other
organs.
The _hedgehog_, _ground squirrel_, the _field mouse_, _house mouse_,
_mole_ have been successfully inoculated.
The _frog_ immersed in water at 30° C., forms a good culture ground for
the bacillus which may be found in its blood, in pure cultures, from the
second to the fifty-fifth day. These cause no local lesion, nor obvious,
constitutional disorder. It seems possible that, in summer, the
infection may be propagated by frogs in the drinking water.