Dry season bovine fasciolosis in Northwestern part of Ethiopia

Features of dry season bovine fasciolosis were studied in North Gondar area , Northwest Ethiopia. Out of the total 2226 cattle examined, 774 (33.42 %) were found positive on qualitative coproscopy. The overall herd egg output (EP2G) was 81.16 +/- 0.11. The herd infection prevalence, as estimated from the egg-shedding index, was 41.22 +/- 4.38. In all the above measurements, the monthly values significantly decreased (p < 0.05) along with the progr ession of the dry season (November through April) and with an increase of a ge. The abattoir-based study on older stocks revealed an overall fasciolosi s prevalence rate of 90.65 %, without any statistically discernible variati on (p > 0.05) between study months. Infections due to Fasciola hepatica, F. gigantica and by both fluke species occur in the order of 67.14 %, 14.1 % and 18.77 %, respectively. Moderately affected livers present the highest m ean fluke count (112.73 +/- 2.3) followed by severely (61 +/- 2.2) and ligh tly (32.09 +/- 2.72) affected ones signifying the presence of acquired resi stance and local tissue reaction as chronicity of infection supervenes. The present study suggests that high fasciolosis pathogenesity is present i n the study area, justifying at least one obligatory strategic treatment du ring the dry season. In addition, as compared with classical coproscopic me thods, egg-shedding index was found to be a relatively robust parameter in estimating herd infection prevalence, hence recommended for use in future f ield investigations and monitoring programmes in the tropics where resource limitations often curtail uses of improved diagnostic techniques. Further detailed study could provide valuable information that foster local plannin g and implementation of a more sustainable fasciolosis control strategy for Northwest Ethiopia.