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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    frequently among the slender, delicately-built animals, those bearing in themselves the fully-developed Electoral character, rather than among the large strong animals distinguished for their Negretti character. In his article on Negretti sheep, Settegast mentions that the trotting disease does not appear among the Negretti sheep. Lastly, the disease appears most frequently among the rams, less frequently among the ewes, and only very seldom among the wethers. The trotting disease is most prevalent in Saxony, Moravia, and Silesia, where the Electoral sheep are most favoured, and where the sale for breeding has grown to great dimensions. Wherever Negretti animals, on the other hand, were reared, and the sale of breeding animals took a secondary place, the disease only appears in individual cases or not at all. To this circumstance is due the assertion that the sheep of the south have less predisposition for the disease than those of more northern countries, which are greatly inclined to the disease from climatic influences. The disease only attacks animals of one to, at most, four years of age. It is extremely rare for any sheep below or above that age to get the disease. Richter stands alone in recounting cases in a half- year's lamb and in a six-years' old ewe. Lastly, very delicately-built and very fat animals show, in general, a greater predisposition, especially very lively, immoderately lecherous rams which are, more- over, prone to onanism. Predisposition is inherited by animals begotten by fathers or bom of mothers suffering from the trotting disease. The disease develops whenever the external provocative causes can act upon the animals. The disease may he even hred in animals though it did not attain development in their parents; and titere are not a few cases on record given hy Richter and Richthofen wJiere the rams were healthy hut their offspring nevertheless were trotters. [Italics mine.—J. P. M'G.] The reasons given up to now for the cause of the disease' have been many and various, and, of course, the more incomplete the knowledge of the nature of the disease the less correct they are. And to be quite sincere, up to the present moment the more immediate causes have not been ascertained with absolute certainty. Some, however, may be mentioned which probably do produce the disease; and others, again, which probably have more or less effect upon it. To the first category belong, prolonged, premature, too continuous breeding of first-rate fine-wooled animals. Especially is this so where rams are used up to their twelfth year, when their procreative power is unnaturally worked up. There is also the disproportionate, ex- cessively strenuous, application of valuable rams for breeding purposes for the sake of a numerous offspring. There is the thrice lambing of ewes in two years, and finally, above all, the too prolonged and con- tinuous pairing of animals already closely related. According to historical information given by Seer in connection with the stock sheep-farms of the Electorate of Saxony, a Merino race had been introduced from Spain in 1777, in which consanguine breeding had been steadily carried on. Twenty-five years later the trotting disease was no unusual occurrence. The same thing was experienced at Rambouillet.