WHAT TUBERCULIN IS, AND HOW TO USE IT.

Auckland Star, Volume XXX, Issue 161, 10 July 1899, Page 6

WHAT TUBERCULIN IS, AND HOW TO USE IT.

Unfortunately many of our readers know more than they want to concerning the losses suffered by stockowners owing to the disease known as tuberculosis. By this time almost everyone has heard of tuberculin, the preparation used for ascertaining the presence or otherwise of tubercular disease in an animal. Every intelligent stock keeper ought to know something definite as to the composition of this diagnostic agent, and the method of using it in veterinary practice. The following from the pen of a veterinary contributor to the 'Farmer and Stockbreeder,' giveß a clear explanation of these matters: —

It is generally supposed that tuberculin is a weak-bred tubercle bacillus,1 but that Is not the case; not a single tubercle bacillus is to be found in a gallon of it. The method of manufacture is as follows: The bacillus is put into veal broth, and to it is added one per cent, of peptone and five per cent, of glycerine. In this mixture, kept at the temperature of the body, the germs are allowed to grow for six or eight weeks. It is then evaporated until only about the tenth of the original volume, kept at a high temperature to kill the bacillus, and finally, if carefully prepared, precipitated with alcohol. Only the debris of the dead bacteria remain, together with the products of their life and death. This is the stuff injected into the living animal as a'test for tuberculosis. HOW TO DO IT. There is no secret in applying the test but carefulness. Certain accessories are necessary, and these are a hypodermic syringe, a five per cent, solution of carbolic acid, soap and water, and a clinical thermometer. It has been stated in this journal that tubefculin is not wholly reliable, and such is, of course, the case, even with the most careful operators. Bang, the great Danish authority on the subject, only claims for it that about 99 per cent, of reactions are reliable, but still, that is something, and under certain circumstances, which will readily occur to the minds of readers, it nay be worth while to put it to the test. The syringe costs about half-a-sovereign, and the 'stuff' something like fourpence per head of stoclt; the other things a few pence; the accuracy of the trained veterinarian, a great deal. It is not every farmer who is heavyflsted, or unable to undertake a simple operation, and we give below simple instructions for those who wish to do it themselves, for themselves., and by themselves. First, as above surmised, you must have the instruments and materials; next, the cattle to be tested must be in health at the time, and not bulling or travelled, excited by dogs, or worried by the loss of a calf. It will be remembered that the Royal Commission, which lately sat for so long, and took so much evidence, came to the conclusion that under certain conditions tuberculin was a. valuable aid to diagnosis (page 4, April, 1898), and 'entertain no doubt as to the value oif tuberculin, provided the test is applied by a competent veterinary surgeon, and that the tuberculin is of trustworthy quality.' On page 3 of the same report, Dr. Sims Woodhead soys: 'As regards the tuberculin test, there could be no doubt that the prethis way. The farmers preferred to senoe ol tubercle could be determined at a much earlier stage than was at one time possible,' etc. Having ascertained by the thermometer that the cattle are in health, and the heat of the body normal (101 degrees to 103 degrees Fahr.), proceed to wash a few inches on the side of the neck-bones, to clear it of muck and scurf; next sponge it over with the 5 per cent, solution of carbolic acid, then having yoxir syringe ready pierce the skin and INJECT THE PROPER DOSE of the fluid. The 'proper' dose, I have said, because it is made in all sorts of strengths, and the chemist who gets it for you will tell you the quantity, or more probably the label , will do so, for without, it the veterinary surgeon is as much in the dark as the novice. It certainly ought to be Xtnade of one standard strength, but it isn't, and we must, as practical men, deal with things as we find them— only be sure as to how much you ought to use. Again, a slight young heifer will not require quite so much as a big old Shorthorn or Hereford. Supposing, then, you have not bungled over the simple operation of injecting the fluid—and I really don't see why any intelligent man should—you have next to watch the temperature. No one is in a better position than yourself to do so, since your business or meals will bring you home at frequent short intervals. At the seventh or eighth hour take the temperature, and note it down before that taken before the injection. Take it again evefy three hours, and if you find that the temperature rises steadily to about, or above, 104 degrees, you may

be pretty sure that tubercle is forming or formed in 90 per cent, of the cases you test. Where you are most likely1 to stumble is in the reading of the thermometer. There may be a very sudden rise to, say, 104 degrees, and as sudden a decline. That means a chill or something else, not tuberculosis, and i a mark should be put against that cow's name as not tested, but to bo tried again in a month's time. If the rise of temperature is steady and continuous from time to time as tested, then, as said before, it has significance. THE USE OF. THE TEST. i It may not be to the interest of | practitioners of veterinary medicine \ that stock-owners should do these things for themselves, but those who claim to belong to & liberal profession are bound to live up to their traditions, and encourage the farmer to ! adopt every means of saving, himself j losa, and why any careful man cannot i carry out these instructions the writer 1 cannot conceive, but for* the fact that he has met men, in all professions and trades, with hands like legs of mut- ! ton, and no capacity for learning anything- without, a long apprenticeship. As it has been shown in speaking of the method of preparation of tuberculin that no bacilli are in it, the ob- ! jection of having animals, 'inoculated,' | as our farming friends insist on calling it, is really not a forcible one. Wo beast is the worse for it, and those !already infected can be weeded out,: and if not kept apart, fatted off and got rid of, whether the owner agrees with the writer or not, in. believing it to be hereditary in its tendency. Scientists assure us that it is not, and that it is only due to infection. We can make uae of their inventions and keep our opinions, too, if we like. They may explain that the offspring of some animals are more liable to infection than others, but that is only another way of putting it, from a practical farmer's point of view. The .objection to selling, subject to the test, whjojb may make a deal 'off,' J because of a -reaction, is one few ! stock-owners care to entertain, and ! home,-testing will save them' from it. jWe are not suggesting' a fraudulent I use of tuberculin to deceive the pur- '- chaser or his appointed veterinary sur- ; geon, but to let the seller find out for i himself which are affected, so that ;he may sell to either the butcher or | the Intending breeder with more asj surance.—'N.Z. Farmer.'