Comparative Efficacy of Three Anthelmintic Programs in Working Equids in Egypt

Comparative Efficacy of Three Anthelmintic Programs in Working Equids in Egypt

Several studies have identified gastrointestinal parasitism, particularly strongyle infection in working equids as a major problem. Furthermore, anthelmintic efficacy is of great concern regarding recent reports of reduced efficacy throughout the world. 450 working equids (n=150 each of horses, donkeys & mules) were randomly selected, summer 2013. The study was performed to compare the efficacy of the already applied anthelmintic programs Fenbendazole drench (FBZ) and Ivermectin paste (IVMp) versus a novel one (Ivermectin tablets mixed with small amount of feed, IVMt) in terms of fecal egg count reduction test (FECR) and the egg reappearance period (ERP). While FECR or anthelmintic efficacy percentage for working horses, donkeys and mules treated with FBZ was 48.27%, 70%, 48.57%, for those treated with IVMp, it was 70%, 90% and 71.42% and with IVMt the FECR was 90.60%, 100%, and 100%, respectively. Moreover, the ERPs (days) for horses were: 33, 57, and 64; for donkeys 23, 54, and 63 and for mules; 29, 52, and 62 when treated with FBZ, IVMp and IVMt respectively. It was clear that the proportion of reduced efficacy for Fenbendazole was very high, either due to drug resistance or administration error (e.g. the equid spits out the medication), Ivermectin showed a lower proportion of reduced efficacy with evidence of resistance only for working horses. Also Fenbendazole showed very short ERPs and high resistance rates while Ivermectin revealed the expected ERP. Given the ease of administration and efficacy, we recommend that IVMt be considered for other working equid deworming programs.