Efficacy of abamectin against ivermectin-resistant strain of Trichostrongylus colubriformis in sheep.
The efficacy of two formulations of abamectin, i.e. oral and injectable was determined against ivermectin-resistant strain of T. colubriformis in sheep. Twenty-four lambs were infected with 10,000 third stage larvae of ivermectin-resistant strain of T. colubriformis. Twenty-four days post-infection, the lambs were divided randomly into four groups of six animals each according to egg counts. The first group was left untreated and kept as a control. The second group was treated with ivermectin (oral) at 0.2mg kg(-1) body weight. The third group was treated with oral formulation of abamectin at 0.2mg kg(-1) body weight. The fourth group was treated with injectable formulation of abamectin at 0.2mg kg(-1) body weight. Fecal egg count and controlled slaughter tests were employed to determine the efficacy of abamectin (oral and injection) against ivermectin-resistant strain of T. colubriformis in sheep. Reduction in arithmetic mean fecal egg counts achieved by ivermectin (oral), abamectin (oral) and abamectin (injection) was 66, 98 and 76%, respectively 10 days after treatment. Ivermectin (oral), abamectin (oral) and abamectin (injection) reduced arithmetic mean worm burden by 63, 97 and 74%, respectively. The findings demonstrated that abamectin oral formulation was more effective than abamectin injection against ivermectin-resistant strain of T. colubriformis in sheep.
Alka
Department of Epidemiology and Preventive Veterinary Medicine, Punjab Agricultural University, Ludhiana 141004, Punjab, India.
Gopal
R M
RM
Sandhu
K S
KS
Sidhu
P K
PK
D000284:Administration, Oral; D000818:Animals; D000871:Anthelmintics / Q000008:administration & dosage*; D004351:Drug Resistance; D005243:Feces / Q000469:parasitology; D007279:Injections, Subcutaneous / Q000662:veterinary; D007421:Intestine, Small / Q000469:parasitology; D007559:Ivermectin / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000494:pharmacology; D010270:Parasite Egg Count / Q000662:veterinary; D011897:Random Allocation; D012756:Sheep; D012757:Sheep Diseases / Q000188:drug therapy* / Q000469:parasitology*; D014253:Trichostrongylosis / Q000188:drug therapy* / Q000469:parasitology / Q000662:veterinary*; D014254:Trichostrongylus / Q000254:growth & development*
D000871:Anthelmintics; C048324:abamectin; D007559:Ivermectin