GLANDERS OF RODENTS: RABBIT, GUINEA-PIG, MOUSE, RAT.
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.