44 Journal of the Department op Agriculture.. 



THE NODULAR WORM AND THE LESIONS 

 CAUSED BY IT. 



(Oesophagostomum columbianum, Curtice.^ 



By Sir Arnold Tiieiler, K.C.M.G., Director of Veterinary Education 



and Research. 



In the course of the past winter a condition of lambs was 

 brought to the notice of the Division of Veterinary Education and 

 Research, which is caused by the presence of a nematode in the caecum 

 and the first portions of the colon. Many farmers have seen this 

 worm and drawn our attention to it. Some of them were particularly 

 struck by the fact that this parasite was present, notwithstanding the 

 regular and systematic dosing with the drug recommended and issued 

 by this Division, all the more so, because at the same time they had 

 also noted the entire absence of wireworms in the fourth stomach of 

 the sheep. Some farmers emphasized this fact, stating that although 

 our remedy was very effective against the wireworm, it was not so 

 against this particular worm in the large intestines. This, of course, 

 we knew already at the time of the first issue of the drug, and we 

 claimed only efficacy for wireworm and some effect against tapeworm, 

 which effect was noted quite incidentally during the course of our 

 investigations. As far as the nodular disease is concerned the state- 

 ment was made that sheep suffering from it, when dosed regularly 

 with the wireworm remedy, are less subject to the effects of worm 

 infection generally, viz., become less debilitated. This still holds 

 good as far as the ordinary course of events is concerned. It stands 

 to reason that after removal of the more important invasion of wire- 

 worms, a sheep will stand other parasitic infection much better. 



Not all farmers have, however, connected the wasting condition 

 and death of their lambs with the presence of this nodular worm, nor 

 have they noticed the lesions produced by it, although the statement 

 was made by some that wireworms were absent in the stomachs. 

 Probably they had not been making the post-mortem examination with 

 sufficient care. 



The effects of the nodular worm infection show themselves both in 

 lambs and sheep, but more acutely in lambs than in adults. This 

 observation has already been made in previous years and again this 

 year in various parts of South Africa, but more particularly in the 

 Western Transvaal and in Bechuanaland, also in certain parts of the 

 Cape Province, viz., the south-eastern. There seem to be certain 

 years in which this worm causes more damage than in others, and it 

 is possible that the climatic conditions of those years favour the 

 evolution of the worms. It is most likely that the distribution and 

 amount of rainfall are responsible. It is generally stated that lambs 

 under one year of age are most susceptible and that adults running 

 under identical conditions thrive well. 



