Aim: A survey to investigate the prevalence of anthelmintic resistance (AR) in gastrointestinal nematodes on cattle farms was conducted from October 2014 to May 2015 with the common brands of anthelmintics sold in rural veterinary drug shops in Adamawa Region using Faecal Egg Count Reduction Tests (FECRT).
Materials and methods: 172 animals, homogeneous regarding weight and age were retained. Animals with egg per gram( EPG)≥50 were randomly assigned to control and treatment groups. 10 to 20 animals where possible were randomly selected per farm. Animals in the treatment groups were either given subcutaneously: ivermectin1(1ml/50kg body weight), or ivermectin 2 ( 0.2 mg/kg bodyweight), or orally levamisole ( ½ Bolus /40kg equivalent 7.5mg/kg), albendazole ( 1 bolus/80 kg), oxfendazole or a combination of half orally levamisole () and half subcutaneously ivermectin1. Two FECRT methods (Coles(1992): arithmetic mean and Presidente(1985): geometric mean)were used. A reduction of the faecal egg count below 95% plus a lower confidence limit below 90% strongly indicates the presence of AR while the presence of only one of the two parameters suggests an onset of AR.
Results: FECRT results by Coles showed that responses with Ivermectin1 were 64, 81, and 81% in 3 different farms. Those with Ivermectin 2 were 85%, Albendazole 100%, Levamisole 72, 74, 88% in 3 different farms, oxfendazole 85% and ivermectinLevamisole combination 100%. Using the calculation of Presidente, all the % FECRT were above 90%, except for ivermectin1 79%. Cooperia spp was the predominant species on Day0 and Day14, followed by H. contortus in samples on 4 farms post-treatment.
Conclusion: Suspected AR was observed with all anthelmintics, except with albendazole and the combination levamisoleivermectin.
Key words: anthelmintic, Cameroon., cattle, resistance
|
