Abstract
Extract Various aspects of the seasonal fluctuations of worm egg counts in sheep have claimed the attention of many workers and, in particular, a number of detailed studies have been undertaken to examine the phenomenon designated the spring rise or post-parturient rise which occurs in sheep each year with apparent unfailing regularity. These studies have been reviewed by Crofton ( 1954 Crofton, H. D. 1954. Parasit., 44: 466–466. [Google Scholar] ), Soulsby ( 1962 Soulsby, E. J. L. 1962. Animal Health and Production, London: Butterworths. [Google Scholar] ), and Spedding ( 1962 Spedding, C. R. W. 1962. Brit. vet. J., 118: 461–461. [Google Scholar] ).