HELMINTH-PARASITES AND HYPOBIOSIS OF NEMATODES IN NDAMA CATTLE DURINGTHE DRY SEASON IN THE GAMBIA

Three series of necropsies of cattle were performed, corresponding to early dry season, approximately 1 month after the last rains (November , n = 6), mid dry season (February, n = 6) and end dry season (April, n = 3), Eggs per gram of faeces (epg) were determined just before necr opsy; Three trematodes (Fasciola gigantica, Schistosoma spp. and Param phistomatids) and 11 nematodes were identified from cattle, with the p revalence rate varying from 6.7% to 100%. Haemonchus contortus was the most abundant nematode species, constituting from 81% (February) to 3 4.8% (April) of the total nematode burden. The proportion of L(4) (ind icating hypobiosis) of H. contortus was 85-99%, During the dry season, 44-67% of Oesophagostomum radiatum and 8-34% of Cooperia spp, populat ion occurred as L(4). There was no correlation between the number of w orms found at necropsy and the epg. H. contortus survives almost exclu sively as larvae in the abomasal mucosae, whereas Cooperia spp. and O. radiatum survive partly as larvae in the lumen, and also in nodules i n the case of O. radiatum, and partly as hypometabolic adults with hig hly reduced fecundity. Trichostrongylus axei, T. colubriformis, Bunost omum phlebotomum, Strongyloides papillosus, Nematodirus spp. and Setar ia labiatopapillosa occurred in small numbers.