CONTAGIOUS MAMMITIS (CONTAGIOUS INFLAMMATION OF THE UDDER).
As stated in the last article, that form of inflammation of the udder which attacks the gland ducts and follicles, causing deep-seated, hard, nodular swellings, is often contagious. Franck has demonstrated this by injecting into the milk ducts in different cows (milking and dry) the pus from the bags of cows affected with mammitis, or the liquids of putrid flesh, or putrid blood, and in every case he produced acute inflammation of the gland tissue within twenty-four hours. He thinks that in ordinary conditions the septic germ gains access by propagating itself through the milk, filling the milk canal and oozing from the external orifice. He points to this as a reason why dry cows escape the malady, though mingling freely with the sufferers, and why such dry cows do not suffer from inflammation of the gland tissue when attacked with foot-and-mouth disease. In this last case it is evident that it is not simply the inoculation with the milker's hand that is lacking, for the skin of the bag is attacked, but not its secreting, glandular parts. Now that in any case of abscess we look for the cause in the chain forms of globular bacteria (Streptococcus pyogenes), in the cluster form of white, globular bacteria (Staphylococcus pyogenes albus), and in the golden and citron-yellow forms of clustered globular bacteria (Staphylococcus pyogenes aureus and Staphylococcus pyogenes citreus), the formation of pus gives presumptive evidence of the action of one or more of these germs. So in cases of mortification of the bag; in the very occurrence there is fair circumstantial evidence of the presence of erysipelas micrococcus or other germ which kills the local tissues. Again, in tuberculosis affecting the bag (a not uncommon condition), the active local cause is without doubt the tubercle bacillus.
It has been found that false membranes have formed in certain cases of mammitis in the cow, and Klein, after inoculating the diphtheria of man on the cow, found an ulcerous sore in the seat of inoculation and blisters on the teats and udder, in which he found what he believed to be the bacillus of diphtheria. The results are doubtful, even in the absence of false membranes. Löffler, too, in the diphtheria of calves, found that the germ was longer and more delicate than that of man, and that its pathogenesis for rodents was less, guinea pigs having only a nonfatal abscess. The presence of false membranes in one form of mammitis in cows does not necessarily imply its communicability to man.
It has been asserted that scarlet fever has been transmitted from the cow to man, and it can not be denied that in many cases the infection has been spread by means of the milk. The facts, however, when brought out fully have shown that in almost every case the milk had first come into contact with a person suffering or recovering from scarlet fever, so that the milk was infected after it left the cow. The alleged exceptional cases at Hendon and Dover, England, are not conclusive. In the Hendon outbreak inoculations were made on calves from the slight eruption on the cow's teats, and they had a slight eruption on the lips and a form of inflammation of the kidneys, which Dr. Klein thought resembled that of scarlatina. The cows that had brought the disease to the Hendon dairies were traced back to Wiltshire, where cows were found suffering from a similar malady, but no sign of scarlet fever resulted. In the Dover outbreak the dairyman first denied any disease in his cows, and brought a certificate of a veterinarian to prove that they were sound at the time of the investigation; then later he confessed that the cows had had foot-and-mouth disease some time before, and consequent eruption on the teats. So the question remains whether the man who denied sickness in the cows to begin with, and adduced professional evidence of it, did not later acknowledge the foot-and-mouth disease as a blind to hide the real source of the trouble in scarlatina in his own family or in the family of an employee.
In America Dr. Stickler said that he had produced scarlatina in children by inoculation with imported virus of foot-and-mouth disease, but his contention is negatived by the facts that with foot-and-mouth disease constantly present in Europe scarlatina does not accompany it, and that in America, with scarlatina constantly prevailing at some point, foot-and-mouth disease is unknown locally except at long intervals and as the result of the importation of infected animals or their products. Man is susceptible to foot-and-mouth disease, but it never appears during the frequent epidemics of scarlatina.
Among other contagious forms of mammitis I may name one which I have encountered in large dairies, starting as a sore and slight swelling at the opening of the teat and extending up along the milk duct to the gland structure in the bag, all of which become indurated, nodular, and painful. The milk is entirely suppressed in that quarter of the bag, and from that it may extend to the others as it does from cow to cow through the milker's hands.
Another form almost universally prevalent in this district of central New York in 1889 broke out on the teats and udders as blisters strongly resembling cowpox, but which were not propagated when inoculated on calves. It was only exceptionally that this extended through the teat to the gland tissue, yet in some instances the bag was lost from this cause. Scarlatina in man was very prevalent at the time (many schools were closed in consequence), but no definite connection seemed to exist between this and the cow disease, and on different dairy farms there were families of young children that had never had scarlet fever and who did not at that time contract it.
The most common cause of contagious mammitis in cattle is a spherical bacterium in chain form (Streptococcus) (Moore, Ward). Yet it is clear that contagious mammitis is not a single affection, but a group of diseases which have this in common, that they attack the udder.
Prevention.—Prevention is to be especially sought in all such cases. In purchasing new cows see that they come from a herd where the teats and udder are sound. If a new cow with unknown antecedents comes from a public market, let her be milked for a week by a person who does not milk any other cows. Keep her in a separate stall from others, so that there may be no infection from litter or flooring. Wash the udder with soap and water, and wet with a solution of two teaspoonfuls of carbolic acid in a pint of water before letting the regular milker of the other cows take her. If any cow in the herd shows the indurated end of the teat or the inflammation and nodular tender character of the gland, sequestrate her at once and give her a separate milker. If another cow is to be put into the stall she occupied, first clean and scrape it, and wet it with a strong solution of bluestone, 5 ounces in a gallon of water. The milk may be drawn off with a teat tube, or spring teat dilator ([Pl. XXIV], figs. 3 and 4), and the milk ducts injected frequently with a solution of peroxid of hydrogen or iodoform. I have had little success in checking the upward progress of the disease through the teat with carbolic acid or boric-acid solutions. Used on the outside of the other teats, however, they may serve to prevent them from becoming infected. In the absence of peroxid of hydrogen the affected teat may be injected with a solution of 1 grain corrosive sublimate in a pint of water, and the same may be used on the other teats, provided it is washed off every time before milking.
As additional precautions, no cow with a retained afterbirth or unhealthy discharge from the womb should be left with the other cows. Such cows doubtless infect their own udders and those of the cows next them by lashing with the soiled tail. If milkers handle retained afterbirth or vaginal discharge, or unhealthy wounds, or assist in a difficult and protracted parturition, they should wash the hands and arms thoroughly with soap and warm water and then rub them with the corrosive-sublimate solution, or if not, at least with one of carbolic acid. Clothes stained with such offensive products should be thoroughly washed.