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dc.contributor.authorInnes, James Robert Maitlanden
dc.date.accessioned2019-02-15T14:30:47Z
dc.date.available2019-02-15T14:30:47Z
dc.date.issued1940
dc.identifier.urihttp://hdl.handle.net/1842/34742
dc.description.abstracten
dc.description.abstract1. When this investigation was begun in 1935, relatively little was known about the Swayback other than it was a form of lamb 'paralysis". These studies established the pathological nature of the disease for the first time and as a result caused it to be viewed in an entirely-new light, and thus placed it on sounder basis for further important work. • 2. Swayback is a nervous disorder of new-born and young lambs of different breeds occurring in many parts of England, Scotland and Wales. The same disease occurs in Australia and New Zealand and probably corresponds to conditions which have occurred in South America, Sweden, South Africa and India. The incidence in Britain varies annually and may be as high as 90 per cent. of the lambs born on any one affected farm. In some areas (e.g. Derbyshire) the disease is enzootic. • 3. The symptoms are those of a spastic paralysis of the limbs with resultant inco- ordination and occasionally blindness; the disease is progressive in most cases with a fatal termination. • 4. The pathology is characterised by a diffuse symmetrical demyelination of the cerebrum varying in extent in different cases from small foci in the centrum ovale to gross demyelination of the whole hemispheres. Liquefaction and cavitation is a common end stage of the lesion. Secondary degeneration of the motor tracts in the cord is always present. The disease is a degenerative disorder bearing some resemblance to Schilder's disease in man and is of ante-natal origin. • 5. Bacteria and /or viruses are not concerned in the aetiology; "Swayback" is analagous in this respect to the demyelinating disorders in man, monkey and the dog. • 6. The causal agent causes no obvious disturbance in the health of the ewe but exerts a pathogenic effect on the foetus or young lamb. In the latter this agent has a specific affinity for the cerebral myelin and/or for the mechanism or cells responsible for the laying down of myelin which it destroys with singular rapidity. • 7. The suggestion that a disturbance of copper metabolism in the pregnant ewes was concerned in this way with the aetioloty was subsequently investigated. Chemical analyses of the blood and body tissues of "Swayback" lambs and their mothers show lower Cu values compared with suitable controls. The remarkable prophylactic value of Cu is clearly proved as a result of a large scale field experiment carried out in Derbyshire. The exact role which the trace element plays in the aetiology is not, however, understood as it is apparent from the Cu analyses of the pastures that the disease is not a Cu deficiency per se. Until more is known about function of copper and its relation to myelin metabolism, the pathogenesis may not be easily explained. specific anaemic complication in the mother is not part of the syndrome and swayback is not thus a blood-brain complex parallel with pernicious anaemia and subacute combined degeneration in man.en
dc.publisherThe University of Edinburghen
dc.relation.ispartofAnnexe Thesis Digitisation Project 2019 Block 22en
dc.relation.isreferencedbyen
dc.titleA study of "swayback": a demyelination disease of lambs with affinities to Schilder's disease, (encephalitis periaxialis diffusa) in manen
dc.typeThesis or Dissertationen
dc.type.qualificationlevelDoctoralen
dc.type.qualificationnameDSc Doctor of Scienceen


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