Investigation into the disease of sheep called 'scrapie' (Traberkrankheit: la tremblante) with especial reference to its association with sarcosporidiosis.

  • M'Gowan, J. P.
Date:
1914
Catalogue details

Licence: In copyright

Credit: Investigation into the disease of sheep called 'scrapie' (Traberkrankheit: la tremblante) with especial reference to its association with sarcosporidiosis. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

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    viz., an apparently healthy tup and apparently healthy ewe giving rise to a scrapie lamb; and to a less extent a scrapie mother giving rise to a healthy lamb. Such cases do occur, and, taken together with the fact that a scrapie tup would appear not to infect his progeny are circumstances which to my mind cannot be explained on any known theory of sexual infection or even mixture of such theories. It may further be emphasised that were the tup the means of spreading the disease, it is not overstating the case when one says that, taking into consideration the fact that North- umberland and Eoxburgh up till lately supplied a large part of Scotland with tups, a great number of flocks all over Scotland would be infected. This state of affairs is far from being the the disease is authentically known up to the present to exist only in the two counties mentioned. In-breeding and the breeding of high-class stock have been alleged as the causes of the disease. While not actually causing the disease, it would appear that these have a power- ful influence in determining it; for these conditions lead to, firstly, a non-introduction of fresh blood and a keeping up, possibly in an ever increasing extent, of any taint once intro- duced ; and secondly, the tendency to keep alive any animal, no matter what its heredity or what its condition, provided it has show points. As regards the breeds affected by the disease, while all are agreed that the Cheviot, the Leicester-Cheviot, and especially the progeny of the Leicester-Cheviot ram with the Leicester - Cheviot ewe are affected, there is not the same assurance with regard to other breeds, possibly because the disease does not affect them to the same extent. That it does occur in other breeds such as the Blackface, and the pure Border Leicester {vide supra) cannot be doubted, and it is a historical fact that in this country during the latter part of the eighteenth century it occurred in almost all the English breeds {vide supra). In Germany it occurs in the Merinos chiefly, but cases have also been recorded in the South Down. With regard to its occurrence in the sexes, several popular opinions are held more or less strongly. For instance, one common statement is that it occurs principally in tups. As regards the accuracy of this, I may state that while it was