The experiments of Adami show that tubercle is directly transmissible from man to ox though usually with decreased virulence. More recently, Ravenel using the bacillus derived from the mesenteric glands of a child, injected intravenously two tuberculin-tested calves, with 5cc. each of the culture producing exalted hyperthermia, miliary tuberculosis of the lungs, tuberculosis and caseation of the bronchial and mediastinal glands, and death in 17 days. Dr. Garnault’s experiment on himself, now in progress, has already shown the great danger to a susceptible man, of the bovine bacillus.
As showing accommodation to environment, Battaillon and Ferre found that the bacillus (mammalian and avian) grown in frogs, Dubard that grown in fishes, Kráhl that grown in frogs, snakes, fishes and lizards, and Müeller that grown in the glow worm, thereafter grew at summer temperature (68° F.) and grew poorly or not at all in the bodies of mammalia.
The tubercle bacillus is primarily and essentially one, but this must not close our eyes to the fact that in different hosts and environments it takes on very different habits, so that for the time and in these surroundings, it is materially modified in its pathogenic attitude toward different races. Yet its ready variability when conditions are favorable to change, renders it desirable to destroy it in all its forms, and especially in those which approximate most closely to those that prey on man and animals.
An impartial review of the whole field warrants the conclusion that the nineteen young (and therefore comparatively insusceptible) cattle which in Koch’s hands failed to develop generalized tuberculosis after inoculation with the virulent sputum of man, and the smaller numbers that resulted in the same way under similar treatment in the hands of Th. Smith, Dinwiddie and Adami, while showing a very marked limitation in the susceptibility of the sound bovine system to weak bacilli from man, cannot disprove the many well authenticated cases of the transmission of tuberculosis from cow to man and the reverse. The greater potency of the bovine bacillus over that of man, in its action on the small rodents and pigs, utterly forbids the unproved assumption that it is on the contrary harmless to man.
If the object of the sanitarian were merely to delay a fatal result in his tuberculous patient, while he accepted the prevalence of tuberculosis as inevitable for all future time, the acknowledged lessened receptivity of the ox for the bacillus from man would mean more and would be at least worthy of a hearing, but as the extinction of a disease germ and its representative plague must ever be the first object, any movement toward the preservation in cattle of a germ which is deadly to man and much more so to cattle, must be held as subversive of the prime purpose of sanitary work. This is true even if we allow, for the sake of argument, that only a few of the bovine bacilli are capable of dangerously colonizing the human body, and that special environment is needful to allow of such successful colonization. On the other hand the limited receptivity of the ox for the bacillus from man is the greatest encouragement to active work to exterminate tuberculosis from our herds. It is impossible to adopt in man the summary measures that are so successful in the speedy stamping out of the plagues of the lower animals, so that tuberculosis in the human family can only be eradicated by slow degrees, and therefore there will long continue for our herds the danger from the human side, but just so far as the susceptibility of cattle to human tuberculosis is limited, in the same ratio are our hands strengthened in effective work for the extinction of consumption in our herds and for preserving their soundness after they have once been purified. If they were to be reinfected by the presence of any consumptive person we might well despair of success in face of a wide prevalence of tuberculosis in man, but since it is only exceptionally that cattle suffer from man, outbreaks coming from this source can the more easily be taken care of. In this view tuberculosis is approximated somewhat more closely to the other bovine plagues (lung plague, rinderpest) which can be stamped out with the greatest ease and certainty, so that as a purely economic measure the argument for the speedy extinction of tuberculosis in our herds is reinforced.
TREATMENT OF TUBERCULOSIS.
Like all deadly infectious diseases in the lower animals, tuberculosis is not to be profitably treated as a rule. In the case of specially valuable breeding animals, in which the prospective progeny will pay for large outlay, and when the disease is in its incipient stage, treatment may be warranted. The patient should be thoroughly separated from other animals, kept in the open air, or, in our northern winters, in roomy, well ventilated buildings facing the south, well lighted, kept immaculately clean, frequently whitewashed, and well drained. If there are more than one case every precaution named under the head of prevention must be adopted. Exercise to keep the muscular system in good tone is called for, but never to fatigue. Hence, a sheltered pasturage is ideal. Feeding must be liberal including a ration of grain or seeds, and oil bearing seeds like linseed, rape seed or cotton seed may be specially named. Cod liver oil alone, or etherized is often of great value, with iron and bitters continued for weeks or months. In the case of specially valuable animals one may use a pneumatic cabinet the principle of which is to diminish the air pressure on the body at large by an exhaust, while pure air for breathing, at the ordinary atmospheric pressure, is introduced through a tube furnished with a face piece fitting around closely beneath the eyes. This serves the purpose of attracting (sucking) the blood toward the skin and other tissues from the lungs, which in their turn are compressed by the air at the atmospheric pressure. Pulmonary congestion is in this way lessened, exudates are absorbed, necrotic tissue removed, sepsis counteracted, hæmatosis encreased, circulation of both blood and lymph stimulated, digestion and nutrition improved, and general health invigorated.
Active grooming and even the stimulating effect of cold douches may be invoked, the skin being rubbed actively until dry and warm.
If the circulation is poor, a stimulating steam or hot water bath of fifteen minutes followed by a cold sponge and rubbing till dry may be profitably substituted. In such cases it is well to put a cold sponge on the head while in the bath.
Medicated inhalation is often valuable especially when the lesions are on, or near the bronchial mucosa. In 1868, Dewar met with most successful results from inhalation of sulphurous acid gas impregnating the atmosphere as strongly as the patient can breath without discomfort. His own groom who had given up work because of advanced phthisis, under treatment of half an hour three times a day, became ruddy, gained weight, and betook himself to work again. In rabbits which I inoculated with human sputa, the same year, all died tuberculous excepting one which I fumigated three times a day for weeks. This rabbit remained plump and well.