01833naa a2200253 a 450000100080000000500110000800800410001902400540006010000210011424501680013526000090030352010390031265000130135165000170136465000160138165000190139765000190141665000100143565000180144565300140146365300190147770000190149677300640151515215942023-03-30       1976    bl uuuu     u00u1 u    #d7 ahttps://doi.org/10.1016/0304-4017(76)90071-62DOI1 aDURHAM, P. J. K.  aExperimental Ostertagia spp. infection of sheepbdevelopment of worm populations and lesions resulting from different dose-levels of larvae.h[electronic resource]  c1976  aAbstract: Worm-free sheep were dosed with 8 000, 64 000 or 512 000 infective Ostertagia spp. larvae and killed 4, 7, 10, 13, 18, 24 or 66 days later. Up to day 10 the worm counts ranged from 52 to 86% of the infecting dose and results suggested no substantial reduction either in rate of development or in percentage establishment with increasing dose level. However, a reduction of worm counts, which was substantial at the higher dose-rates but comparatively small at the low rate, occurred after day 10. Gross lesions in the abomasum ranged from little more than the development of a few nodules in the low-dose sheep, to a roughened congested surface with diptheritic membranes and severe oedema in the high-dose animals at days 10?24. These effects had subsided by day 66. Histopathological changes are described. The severity and extent of the reaction was related to the parasite dose-level, but not necessarily to the numbers of worms recovered post-mortem. The rate of return to normality was quicker at the lower dose rates.  aNematoda  aParasitology  aParasitoses  aSheep diseases  aDoença Animal  aOvino  aParasitologia  aNematodeo  aOstertagia spp1 aELLIOTT, D. C.  tVeterinary Parasitologygv. 2, n. 2, p. 157-166, Oct. 1976.