A DANGER TO SHEEP.

Dominion, Volume 1, Issue 110, 1 February 1908, Page 3

A DANGER TO SHEEP.

DESTRUCTIVE FLY AMONG THE FLOCKS. • WARNING FROM MR. GILRUTH. ' A serious danger to tho sheep flocks of New. Zealand is foreshadowed in a bulletin, from thopen of tho Chief Government, Veterinarian, Mr. J. A. Gilruth, just issued, on the sheep-maggot fly. The bulletin' is illus- 1 trat-ed in colours to show tho appearance of tho fly in life. The text of the bulletin is appended:— During tho past summer this pest to the flockowner. was proved to exist in Now Zealand, and though, as yet, definitely-' recognised only '.in; North Otago, in view? of tho .fact that it is,in many parts of. tho .world a 'Veritable . scourge,, sheopowners are cautioned: to be on tho outlook for its appearance among their/flocks,; and to tako ail pos/siblo. precautions to prevent it's spread,' 'as well as its ravages'. If in older countries •with'small, flocks, .under-constant supervision', the'niaggot in certain seasons is a constant source of worry awl ioss .to farmers,- howmuch "more '■■ serious might: it v hot become -in, the '-'Dominion'; where (locks are larger, and •are not', and could: only with difficulty ,;be, subject to the samo watchful care! This is well seen in pertain parts of Now South Wales and Victoria, where of recent years, a species of' maggot-fly, (the nature of which is apparently not yet definitely determined) 1 has -been playing havoc with sheep; and to such an cxtout'.that some reports mention 10 per cent, of cases -as'having, occurred amongst' certain flocks of ,ewes. . Like a Bluc-Bottlc. ' ; 4 .- v - Tho-fly." which we have demonstrated to he present hero by hatching it from tho'laryso (maggots) • is that termed Lucilia sericata. Smaller than tlio ordinary. " blue-bottlo," it is of a greenish-blue tint, but is otherwise similar in appearanco, arid is; frequently, con-. founded with- that fly. In mos,t countries where tho . sheep-maggot is plentiful- tho parent; is popularly considered to "bo the. common- - ' (Calliphora vomitoris;, but this-' is., erroneous. •; The blue-bottlo'-lays,its "eggs on, carrion and liko material!'..''on-..which tho ,' larval' feed ' after hatching,- but- there is-no'.evidence .that they . uro.' capable of existing . and developing on the livo .'animal; at v least,-■* they > arp;, -not capablo of- penetrating the. healthy' shin: - -It' they*' were, it is obvious that sheep-breeding would • -have bceomo almost an impossibility in New .Zealand. long'ago, ... , ' .- . ;Breeds-inithe Wool. - , The sheep-fl v lays its ega:s m the'wool of sheep, particularly .those whoso wool is dirty, lambs and hoggets' suffering - from., diarrhoea and'.'consequent; soiling of the hind-quarters -being-especially prone to. attacks.Sheep and lambs' which- are. free from soiled wool or. not, however,' exempt from attack when the fly ~is prevalent during tlio summer .months', par-ticularly.-towards tho latter end of tho season. -.Showery"weather ; and long grass on dewy; mornings,, rendering .tho: wool .moist,seem'to. exert an influence in attracting the flv. Naturally, wounds and abrasions of the skinJare also likely places of attack.Be2d Carcases Harbour the Pest. Although' tho sheep is generally considered to bo a necessary 'host for the maggot, it is- difficult to seo how this can '1)6- so, -and it is most probable-that any carrion in-warm weather, may offer a suitable' place for the deposition: oi' eggs by thij fly.'-arid the. • subsequent dovclopment.^ncl. growth of. tho larva) ! o'r'. magg'ofs. • v'T>caU : -:^r'ep.i' , .'cspe6ially those left unskilled, in any :'case 'afford an excellent breeding-ground•' i for .tho"parasites:so that ono of the first lilies; of defence is burial of r all dead'shcepso soori as found. •" r.-'- '■ ■ ■ ■■' v How the Damage Is Done. !■: -.. L , ■ In * a comparatively 'short time after the eggs,nro 'laiil tho young maggots arc batched out, • arid ,'immediately: travel, towards', the skin, whero they "induce"irritation' and ihr: fln-mniation, which, is only aggravated by .the attempts of tho. animal toVontain relief. Soon tho maggots''burrow through tlio : skin-and pass: between, .that, and: the \ muscles, and if not observed early they will ultimately .burrow very deeply, cases having been seen;hv tjio writer - in which . they'-hav'o eaten ■ thbir way right i-into tlio abdominal \cavity before' death .of the occurred. ' ' , , ; •■', ./ . Symptoms.".' I The symptoms consist; as may be .expected, of attempts tolreniove the cause .of the irritation, by biting .'the..partj-affected, frequentrubbing, rapid agitation . or .'tho -tail,, etc.; . but this can gcncrally .only bo. observed if flu' animal' is undisturbed, and in. tlui - early- • stages 'before the skin Decomes insensible. .If the skin has become, partially, destroyed ..be'foro'the' allcctod sheep is'.* seen,'; listle'ssriess. may; be tlio .only-'readily discerned evidence,..but a 'careful observer inayr—especially'if the animal is tho,Side,, aslambs frequently jare-^detcct. a damp, dirty-looking patch of wool due to-discolouration by.er.uda-. tion from the skin. So rapid is the ,'wliolo course, of ..events that) .even- in; a, carefnlly ..watched-.flock,, cases of. extensive damage'. are riot rare,' 'and' sometimes . even death 'is '.impossible to prevent. -••.'. ;' ■ ■ PraventiVQ Measures. . ;.In addition' to the burial of dead sheep—■ .ivhich/ by.'removal bf/.a hreedin'g-grouiid,.'pre-vents the, lncreaso of flics to a grent extant —clcanihiess of; woiinds and ,their / proper -antiseptic" treatment,'; thb'-nminteiianco. of cleanliness ;of ' the hind-qu'artcrs' -wool by crutching, -(lagging, etc.,.,where necessary, will,go. far',to prevent -'the;-fly''".striking;": Diarrlicea should, bb treated by' reiiiovai; different paStnr'e, and, if necessary, tho provision of, dry food. In addition-.to all- t-nis, dipping', by " means" of ' ail offcctivc: lasting dipVas a.-preyentivo i?'-strongly 'recommcrided ■ for. any -HoclV m.-. which', tho troublo,' has ap'pearcd, or is likely to appear." . Curative Treatment; ' This - should ibo adopted ,-a sheep is observed to :bo "• blown."-- All dirty or ■ mattfcd- wool should bo. removed' by tho shears, arid, a, strbng solution of non-poisbu-bus" shebp-dip or othor'similar' antiseptic' npplicd 'to . tho ' part' where' tho maggots' are located! A' good ..mixture.- -is 'onb.part of oil of turpentine to three' parts" of olive-oil, the whole being well shaken up bofore applying!. The greatest car© is necessary in order, to- destroy all the maggots, as whenever/.tbc wool is disturbed,: anu especjally." when it is .being.' clipped,'.- thoy' inimedir ately endeavour tb bury, themselves ,anioiigs6 tfie siirrounding wool. It is always advisable, therefore,-to examine a dressed animal, on subsequent days in order to ascertain if any maggots lidvo escaped, and especially: to ,bei icertain that, it has not—as frequently happens—been. again " struck." . . ' •