Variation in faecal worm egg counts of experimentally infected goats and mice with time of day and its implications in diagnosis of helminthosis.

Faecal worm egg counts (FEC) are very important indicators in assessing the intensity of helminth infections in animal hosts and inform decisions taken in parasite control programmes. FEC are however affected by many factors which include the dose level of larval challenge, species composition of the worms, worm burden, female worm fecundity and concurrent infections to name but these few. The relevance of time of collection of faecal sample for FEC is not fully known and in most cases faeces for analysis is collected whenever feasible for the researcher on sample collection days. The significance of the time of collection of faeces on FEC was therefore investigated at two different periods of the day, morning and afternoon. Faecal samples were collected at 7-8 a.m. (morning) and at 2-3 p.m. (afternoon) on same sampling days from 6 mice and 10 West African Dwarf goat kids experimentally infected with Heligmosomoides bakeri and Haemonchus contortus respectively. FEC were conducted using the flotation and modified McMaster techniques. Overall, the 2-3 p.m. FEC tended to be higher than the 7-8 a.m. FEC in both animal species but the difference was not significant (P > 0.05). The time of collection of faecal samples for faecal worm egg counts is therefore not a crucial factor that may significantly affect FEC in H. bakeri and H. contortus infected mice and goats respectively although it would be advisable to maintain particular periods for collection of faeces in particular experiments for best results of FEC to be obtained.