Brock, RM

Engels, EAN

Groenewald, HB

Hattingh, A

Hofmeyr, HS

Hunter, Pamela

Joubert, JPJ

Mitchell, G

Newsholme, SJ

van der Veen, RR

English

AJOL - African Journals Online

Stress factors associated with nutrition in the subtropics and tropicsOvine wet carcasssyndrome of unknownaetiologyR.M. Brock, J.P.J. Joubert, A. Hattingh, G. Mitchell,S.J. Newsholme*, R.R.van der Veen, H.S. Hofmeyr,E.A.N. Engels, H.B. Groenewald and Pamela Hunter*Address correspondence to:Dr S.J. Newsholme, Pathology, Veterinary Research Institute,Onderstepoort 0110 South Africa.A condition of unknown aetiology, known as 'the wet sheepcarcass syndrome' has led to the loss of about R500 000 as aresult of the condemnation and trimming of carcasses, duringthe past 2 years. An affected carcass has a shiny, wet appearancedue to the accumulation of watery fluid in subcutaneous tissuesover the buttocks, sides and flanks. It cannot be diagnosed inthe live animal.'n Toestand waarvan die oorsaak onbekend is, staan bekend as'die nat skaapkarkassindroom'. Dit het 'n verlies van sowatR500 000 veroorsaak in die afgelope 2 jaar, weens die afkeuringen gedeeltelike regsny van karkasse. 'n Aangetaste karkas het 'nblinknat voorkoms as gevolg van die aansameling van waterigevloeistof in die subkutane bindweefsels oor die boude, sye enflanke. Dit kan nie in die lewendige dier gediagnoseer word nie.Keywords: Ovine, wet carcass, non-inflammatory, unknownaetiologyIntroductionWet sheep carcasses were seen with increasing frequencyat abattoirs from January 1981. They were unacceptableto the consumer due to poor keeping qualities and un-aesthetic appearance. This resulted in the condemnationof about 90 000carcasses valued at R400 000 and the lossesdue to trimming of other carcasses amounted to R100 000or more over the past two years.The syndrome is characterised by the accumulation of awatery fluid in the. subcutaneous tissues covering thebuttocks, sides, back and flanks of such a carcass. Thiswatery fluid also occurs in the intermuscular connectivetissue layers of the flanks and subscapular area. Theinside of the skin has the same wet, glistening appearance,which is easily recognizable even at a distance of 10metres.Results and DiscussionAppearance of a wet carcassThis can be seen in Figure 2, where colour photographs ofwet carcasses are presented.Animals affected, incidence and area of originThe condition is commonest in Dorper sheep, but it alsooccurs in Karakuls and to a lesser extent in Merino-crosses. Most sheep are marketed at 4-8 months of ageand hence this age group is most affected. The syndromeis prevalent in sheep of the Gordonia district and adjacentareas, with only a few cases reported from the SouthernOrange Free State (See Figure 1). The incidence variesSO UT H IOTSWANA.WESToAf RICAFigure 1 Map of the Republic of South Africa showing the area oforigin of wet carcass sheep.markedly between lots from the same farm and averagesabout 4,5% for the whole area. Wet carcasses occurthroughout the year and a few have even been reportedon the farms of origin. A large number of wet carcasseswere graded Super Lamb and Grade 1, demonstrating thateven the best grades are affected.Clinical pathologyThis condition cannot be diagnosed in the live animal,therefore analyses of preslaughter blood specimens werecorrelated with postslaughter findings. Total serum protein,albumin globulin ratio and electrolyte levels of wet carcasseswere normal. Liver specimens (kindly analysed by Roche,Switzerland), revealed normal vitamin A levels and sig-nificantly higher than normal vitamin E levels for wetcarcasses. Interconnective tissue fluid contained less totalprotein (10 gll as compared to 45gll) and relatively morealbumin (albumin/globulin ratio of 2,5 as compared to1,2) than that of normal sheep.Other investigationsAt the abattoir, the following possible causes of thesyndrome were eliminated: washing carcasses with waterS.Afr. J. Anim. Sci.  1983, 13(3) 195(a) Wet carcass with intermuscular connective tissue layers displayed. (b) Hindleg with accumulation of watery fluid in subcutaneous tissues.(c) Watery fluid in flank area.Figure 2 Photographs of wet carcasses.under too high a pressure, faulty cooling systems, feed inthe holding pens, and transport stress.In the high incidence area (see Figure 1), feeding systemsvaried from feedlots to 100% grazing on grass and shrubsof the Kalahari. Water from these areas was good andvery potable. No plants, thought to cause this conditionwere seen and the vegetation differed widely from farm tofarm.No viral or bacterial organisms capable of causing thecondition were isolated.Apart from the fluid in the loose connective tissue, noother macroscopic pathological lesions could be seen.Histopathological examination, showed no evidence im-plicating cachexia, inflammatory processes, lymphoedema,cardiac failure, glycogen storage or myxoedema in thepathogenesis of the syndrome.In conclusion, despite intensive investigation the aeti-ology of the wet carcase syndrome remains unknown. Atpresent the possibility of a histamine reaction due toinsect bites is being investigated using the 'Kalahari sandtampan' (Ornithodorus savignyi), since it occurs in themajor part of the Gordonia district.(d) Subscapular area with fluid accumulation.--

Ovine wet carcass syndrome of unknown aetiology

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Ovine wet carcass syndrome of unknown aetiology

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