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TECHNIQUE OP THE METHOD.
The following description of the technique of the method of preventive inoculation for tick fever, as embracing the results of the la test experiments, has been prepared and
pnoiied in pamphlet lorm bj .>u\ C. J. Pound, Director of the Queensland Siccli Institute :— NECESSARY APPLIANCES. By carefully considering the following direction*, any one accustomed to wok among cattle may be able to perform the necessary operations without personal In struct iona. The curator muse, be provid-d with ftoe following nee.s»ary appliances:—
1. Six feet of whipcord. 2. Trocar and canula. The laUer sliouid not be less than %ln. d'ameter. 3. Synnge t- hold 10 c.c, fltted with abeu: Sin. of thick-wall d rubb r tubing, and ono or two of the improved needles. 4. Two large w:de-mciuh J.irs or jugs, to hold about 1% pints each. 5. Two email wide-mouth bottles, to bold about 2oz. <ach. 8. Twenty to thirty fowl-win* fea'her», pre viously washed in strong carbolic solution, 1 in 20, then In clean water, and finally dried In the sun. 7. Several pieers of dean linen or calico. 8. Clinical thermometer. 9. Ntii^r—For itbe Inoculation of largo herd* of ordinary ttatlcn or wild cattle In a crush, some additional appliances are found to be absolutely necessary. At flrat a by-way Up was used, but, in con<>cquenco of the possibility of so many errors o.cur rln« through the operator' tuning the tap the wrong way, this accessory ha* been superseded by a spdaily designed doubl -• action valve made in two separate pieces The larger part A, with two nozz'es, is fltted on to the front of the eyi'ige ; ti ■the upper or 'ong nozzle is attached s m 10ft. or 12ft. or ihick-walled (small apertur 0 rubber tubing ; at the otver tnd of ihl« tub ing Us fixed the inocula'lng needle.. To the •mailer or lower nozzle is attached about 30in. of the same kind of tubing, the op posite end of which ,is iixed on to the small er part B. which l«.>plared In -»n "nrl«?V p ni tl'-.n at the bttom of a small soda-water Jwttle, wtirh \9 Vent fn tv<» ton •« ocr.e; of the oDerator in charge of he «yrlnge. PREPARING CALVES FOR THE SUPPLY OF IMMUNE BLOOD. The overwh?)ming evid nee, remltng from the most crucially conducted exper'menH, and the extensive practical exp^rUne of a large section of keen observant sto^kowners, prove beyond all doubt the efn>a"y of the imethod of preventive Inocutaion for tick fever as first Initiated in the Mundoolun and Inkerman experiments of April, 1807. Although the artual me'hod of drawing the blood and injecting the same in o animals to toe protected has not been improved up^n, still, in addit'on f> the various improve ments in the Inocula'lng in tntmens, there have also been several modifications in the imethod of rendering th" blood rt animals suitable for g ne-al i-*ioculatl<-n purposes. The number cf cilvcw required to supply Wood naturally depends in a t;n-at measure on the size of the h«»rd, or, in f'ct, the n"ra bpr of animal* *n b° in'"cv'a4'''d R"i"| ence lias ftown that twelve yearling heifers "Will providn sufficient bod io in cv a c a herd of 20,000 cattle ; while it is recorded
that 8000 and eveu 10,000 cattls have all 'been efficiently Inoculated with the blcod from only four animals. For g mral Inocu lating purposes the blood of an animal ar ttftc a ly inoculated c to be pie erred to thac from an animal recovered from natural tick -fever, the mode of operation being as fou« 1 wa :—Procure the deMred number of healthy yearling calves (heifirs, ir possible), *nd a supply of frcehly-drawn deftbrlnated <b ood from a natu <al'.y rec-v rel an m 1. Tti? bfst way of operating U to th ov each on its left side ; Che leg* may be either tiel or held by an assistant ; the head is covers •with « bag, which makes line animal He quie.ter than it otherwise would do. By meane of the piece of whipooard wht<dh ia placed round the base of tho animal's neck w th a rum n« noe\ the right Jugu ar vein is compressed co that in a few minutes il ib?comes d rated or sw 11 nby n? bkio lem ing from the an mala bead. A vrry nee s «ary precaurinn will be to ftaten the 'bair on the skin covering the vehi with a little s lu tlon of 1 in 20 carbolic acid : thie removes any danger of Introducing foreign matter ■whlr-h m gfht prrduc > bl;-od-p laonl g or »i ab^cees under the ©kin. The calf la ly'ng oa the ground with its feet from the op«rat>r, who, standing behind, lays li'a left hand on the neck and gently hclds the «woll?n vain in a steady position between the foreflngw and thumb close up to the cord to prevent tfte vein from ehirting laterally. H.-j then •takfa the Improved needle in he rlgfa! ha-<l, and steadily plercrs the skin Into the vrm. If the vetn has been pierced eucc-reerudly, blcod wiiH spurt out. An assist nt then I hands the cprnat r the syringe filled wllh 10 c.c. of the recovered tick-fever blood. The nozzle of the syringe !e then laimedi-ateiy connrcted with t>ie needle >by means of a emr.H piece of rubber tubing 'in isuoh a mas i ncr that there is an unlnterrurt d c>lumn of blrcd fr. m t^e vrtn to the pnd of th-» p's ton-rod o-f the syringe ; for ll'e fact musi n-t be cver'o-'ketl that a s-nall bubble <•* cl i 5nJ -cted into the b'.od-vces I may caus? ln- Etant death of Kip animal. Directly the sy ringe ta coupled with the ne*dl» the c"rd is removod from the neck, «nd the blcod ejeteel fr^m the ©yr'nee into the vein. It is a<3 vk-oiblo on withdrawing the n'-edl^ f> p'^ch
•the skin around the wound and *>pplv a 1 t t'e mrr-1 carbolic ©n'ution b^f^re rel asl'ig the animal. After each cilf has been In cu latr-d, rhey fhoud be kept in a well-gra< eM pad «k wMi'pl ny of fr *h wa'er, and thel tempratures taken regularly night and morning from the eighth to the twenty fourth (lav nft^r inrxnil^tlen. Ti-O3r <g vl g a very derided reaction —Daraely, tempe-a ture rslng from the normal (lOLSdfg. P br.) to 106deg. Pa-hr. or higher—are. when they have completely recovered (which will t>6 wtrh'n six we°ks). f-u t 'ble pubj'c1® for draw ing blo^ from for gpnerel- Inoou'atl n pur poses, and are generally spoken of a© " Im mune calvea." T.be reasons why ynung a.nl n>a"s are prrferr d a'-e :—(1) ai hy are eaallv !handlPd and managrd. (2) Tbe sub titarew* t!«/»iie of the neck between the Jugular v in and the sWn is not very thick. (3) In in cu leting blood from a calf there is very Uttlo rl-k of introducing tuberculosis, wMeh ta wldom found in calves ; howrvr. rtn firder f» mlnlmrtae 'any pore ble risk from thla d s*m the calves can be all previously tested wl:(h
•METHOD OF DRAWING THE BT.OOD FROM THE IMMUNE CALF AND PRE PARING SAME FOR GENERAL INOZU LAiION PURPOSES. The imitmine elf :s thrown on 'ita l2fl eid?, and a crsrd tigh-teDed round the neck m pre vloualy dfßcrlbed, (but instead of a needle fhi operator lakce the trocar (wl h ca:iu a at tached) in lii? right hand, and with It in a vertical peel Won steadily pierces the .'/kin dnto the vein. Immediately the point is through the wall of the blood-vo:cel, tha in strument is 'held in a alantlng pceltlun, and gently preeaed further 'into the distended vein. The operator then withdraws the tro car with the right hand, the wfoila holding the ahe&lh or canula with 'his 1 ft, and keep ilng it well into tflie blood-veesel. If the vela baateen «ucct«fu ly pierced, blco3 will fliw copiiousiy. If it dc« 3 not flow, the jp rafor rcturne the trocar i .to the sheath and genUly witbdrawe "both of them a very slight distance but not out of the wound, because at the first Insertion the trocar may have been forced through the vein or on one wide of it, which orten happers in the case of young thick-necked bull-*. How ever, as coon as the blood flows freely oa withdrawal of the trocar tt is caught in a perfectly clean wide-mouth bottle. From an animal six months old half-a-plnt of b'.ood may be taken, and as much ao a pint and a-'half from a yearling. In the summer time, when the flies are plentiful, • little tar should be placed on the wound bef r; the calf is released. As soon as the re quisfte amount of Wood is drawn it should be well stirred for about five minutes with a wtofak formed of ha##-a-dozen wing feathers from a duck or fowl. At the end of that time the whisk, when lifted out, will be found to be covered with strlngy-like flbrinous blood-stained matter. This kr the fibrin, and its removal prevents the bleoi thickening, clotting, or coagulating. Tbs process of whisking and removing th<» fibrin is known as dpflhrlnation. Deftbrinatexi blood is that which has been so treated. The blood i« afterwards strained through a. piece of clean linen or rallco into another clean bottle, and Is reaflv for use. DETAILS OF THE PROCESS OF INOCULA TION. Allowing 5 c.c, which U equal to one tea spoonful, for one bullock, one pint of d> fibrlnated blood would be adequate to In icu late about 100 cattle. To mm mise, as far as possible, the risk of contamination, the following 'precaution may be adopted : —Th3 operator puts about 2oz. of blood from the stock bit'le into a small wide-mouth bottle, which Is covered with clean linen or c lico. The small bottte is for actual work of inocu lation, and should be filled up as required.
Inoculation should be performed without delay. Ordinary etatirn cattle to be ino culated should be placed In a crush, and as many as possible at a time, so that the work may be carried on quickly. Dairy cattl? may be secured in a ball ; while young calves may be held against the rails in a s ©;kyard. The syringe now comes into use, And a word or two of description here may be usef .1. It to in principle like a equlrt or garden syringe, but Bhould have the wry latest Im provements. The cylinder or barrel ahou.d be made of stout glass to nold 10 c.c. with metal protecting sides, on each of wh'ch atv fixed either a metal ring or a 'projecting piece to enable the operator to inject the
5 cubtc centimetres cf blosd can be injected. The above d-iTlptUa nnly refore to svrlnges *Tl g the figures 1 to 13 on ite plrto rol readiug frtm cue ha. idle to .he rubber plunger. With each syringe there is usual ly supplied one or more hallow needles, ouch having a metal socket wh.ch (is en to iha nozzle-point of the metal p otect r of the glass cylinder. As the snmala shrink and unove suddenly from the needle when thrust into them, It Is very apt to get broken o.v- Lng to Its being rigidly at.ached to t^a syringe, and on account of its very tiiu wall with large aperture, which is liable to become clogged when passing through :us skin; consequently another needle has been
blood with one hand. The plunger on the pteton-rod should be made of rubber. In the latent form of syringe there Is a very ingenious device for tightening or slacken ing the rubber waaher of the piston-rod without removing the latter from the cylin der. On the glass cylinder of sozte kinds and on the pteton-rod of others (the latter preferred) there will be coilcsd a row of figures, each one above a transverse lino. The space between each line indicated ie 1 c.c. (cubic centimetre)—that i« to say, when the piston-rod h»s been withdrawn until the figure 4 is visible, there will be 4 cubic centimetre* of space in the cylinder of the syringe! On the piston-rod of all modern syringes there is also a little sn screw which can be screwed up and down to any part of the rod ; then fore, if. the syringe is flret filled with b'.ood and the cet-'screw turned down to the figure 5, ouly
designed. The to proved needle hai a ama'l er aperture with thick wall, thus enabling the point to be sharpened on an oilstone lik» a lancet. The needle la fixed in a small metal handle with depressions on ether side for the thumb and finger aud a circular shield in front which en able* the operator to have « firmer grasp. Instead of being fixed rigidly on the eynuge, v it ii connected by moans of about 2in. of 'thick-walled indlarubber tube, one end of wliich flta on to the nozzle of the syringe, w-hile the other Is attached to the handle of the needle, thuo giving free play to the syringe when blood is being injected into an animal, a\l the operator has more freedom Id using It. The tubing should be three eighths of an itch In diameter, and the walfr bo thick that the aperture is only one* sixteenth of an inch in diameter. Thick tubing does not kink and stop the ficv ot
IMPROVED SYRINOB FOR CATTLE INOCULATION.
blood, even when turned at right angle*. Thp instrument, having been made ready by fitting on the tube and needle, 1b filled with Wood from the small bottle, and the eot acr«w fixed at the figure 5. Aa explained above, the inoculation of calves for subse- Quent supply of blood takes place direct Into the jugular vein, but this ,proce©j could not be carried out In Inoculating cattle generally aa a preventive agolpcrt .tick fever. However, the following Id the method in use at the present time, and "flrhoreyer adopted, bas given Batlsfactory reaulto : —A-little fold of looße ekln behind the shoulder of the animal to be Inoculated 1b lifted from the ribs with the left hand. The needle, with tfc••> flattened edge outward, io then plunged with a sudden thrust obHquely about an Inch through the skin Into the loose or oubciltT aneoue tlseuo ; thereafter the piston "la pres sed very slowly down, and the blood forced Into the animal. Although practical experi ence has proved that behind the shoulder is tin most favourable site for the inoculation. It may bo accomplished, when aeceeoity erires. In eny other part of the body where the skin is 'loose. But animate should not be Inoculated in the tail, the reasons being, in the first place, that the tail is exceeding ly sensitive, and the needle Is more apt to get broken in it than in any other .portion of tho body, and, in the second place, that it lo impossible to Introduce the required amount of blood. The blood having been transferred from the syringe to the beast,, the operation lo complete. It ia not -neces sary to take the temperaturea of the animate afterwards, as if prope> lnood to used the Inoculation seldom--fails. (To be continued.) .•»-'