Abstract:
A cross sectional study was conducted from October 2020 to August 2021 at two selected
districts in central Gondar Zone with the objectives of identifying the major ixodid tick species,
estimating their prevalence, investigating their associated risk factors in cattle and to assess the
efficacy of three commonly used accaricides in selected district against tick infestation. A
multistage cluster sampling method was used to select animals from each household for
prevalence study. Infested animals were selected purposely for invivo accaricides efficacy test
while animals which have engorged ticks were selected for invitro efficacy test. Tick species
were identified by using morphological identification keys under a stereomicroscope. Out of the
total 1200 cattle examined, 570 (47.5%) were found to be infested by one or more species of
ticks. A total of 5480 adult ticks were collected and identified to genera and species level.
Amblyomma 2649 (48.3%), Rhipicephalus189 9(34.7%) and Hyalomma 932 (17%) were the
three genera identified during in the study areas. Amblyomma variegatum was the most common
species with a prevalence of 26.33%. For invivo acaricide efficacy, amitraz was significant in
infested cattle from Day 1 to Day 21 post treatment as compared to Ivermectin and diazinone.
For the invitro technique, a total of 480 engorged adult female ticks were collected and the
standard modified adult immersion test (AIT) was employed for three successive trial. Engorged
ticks dipped with Diazinon at 0.06% solution, A. variegatum (%C= 90.52%), Rhip (Booph)
decoloratus (%C=90.67%) were laid eggs whereas A. variegatum immersed in Amitraz 0.025%
(%C=96.54%) and Rhip (Booph) decoloratus (%C=93.96%) were laid small batches of eggs.
All of the ticks in the control group (100%) were laid eggs. In conclusion, the prevalence study,
acaricide efficacy test and questionnaire survey indicated that tick infestations were the most
important problem of cattle in the study area and hence appropriate control measures including
regular surveillance and using appropriate accaricide should be implemented to mitigate the
problem.