On the morphology, growth and identification of the pre-infective larvae of some horse strongylids

Abstract

Descriptions are given of the first and second-stage larvae of Strongylus edentatus, S. vulgaris, S. equinus and Trichonema nassatum and newly hatched larvae of Trichonema catinatum and Triodontophorus serratus. Information has been obtained on the growth of pre-infective larvae and on the structural changes which occur during the first ecdysis. Most of the species of newly hatched larvae studied can be differentiated on the basis of differences in appearance, dimensions and other morphological features. The advantages of differential diagnosis of horse strongylid infection using first-stage larvae rather than infective larvae are discussed.My thanks are due to Dr H. D. Crofton for his constructive criticism and advice and to Professor H. E. Hinton, F.R.S. for the provision of laboratory facilities.This work would not have been possible without the willing co-operation of Mr L. J. Potter from whose slaughterhouse the parasites were collected. I am also indebted to the Horse Race Betting Levy Board for their financial assistance.