Anthelmintic efficiency of doramectin, fenbendazole, and nitroxynil, in combination or individually, in sheep worm control.
The anthelmintic efficiency of doramectin, fenbendazole, and nitroxynil, used individually or in combination, was determined by the Fecal Egg Count Reduction (FECR) test and cultivation of larvae of anthelminthic-treated sheep grouped as follows: G1 (doramectin), G2 (fenbendazole), G3 (nitroxynil), G4 (doramectin + fenbendazole), G5 (doramectin + nitroxynil), G6 (fenbendazole + nitroxynil), G7 (doramectin + nitroxynil + fenbendazole), G8 (untreated). In addition to individually used doramectin and fenbendazole, the helminths were also resistant to the combination of doramectin + fenbendazole; nitroxynil + fenbendazole; and doramectin + nitroxynil + fenbendazole, with their FECR rates ranging from 62-83%. The helminths showed possible nitroxynil-resistance, but had low resistance when the drug was administered in combination with doramectin. The evaluation of individual helminth species revealed that fenbendazole was fully effective against Cooperia; doramectin (G1), moderately effective against Haemonchus and insufficiently active against Cooperia; nitroxynil, effective against Haemonchus and insufficiently active against Cooperia. It was concluded from the results that herd nematodes are resistant to doramectin, fenbendazole, and nitroxynil, and that the combined use of the drugs not only fails to significantly improve the anthelmintic efficiency against Haemonchus and Cooperia, but is also cost-ineffective.
Setor de Veterinária e Produção Animal, Universidade Estadual do Norte do Paraná - UENP, Bandeirantes, PR, Brasil.
Luciane
L
Holsback
Universidade Estadual do Norte do Paraná - UENP, Bandeirantes, PR, Brasil.
Pedro Alex Ramsey
PA
Luppi
Universidade Federal do Mato Grosso do Sul - UFMS, Campo Grande, MS, Brasil.
Camile Sanches
CS
Silva
Universidade Estadual do Norte do Paraná - UENP, Bandeirantes, PR, Brasil.
Gustavo Kremer
GK
Negrão
Universidade Estadual do Norte do Paraná - UENP, Bandeirantes, PR, Brasil.
Gabriel
G
Conde
Universidade Estadual do Norte do Paraná - UENP, Bandeirantes, PR, Brasil.
Hugo Vinícius
HV
Gabriel
Universidade Estadual do Norte do Paraná - UENP, Bandeirantes, PR, Brasil.
João Vitor
JV
Balestrieri
Universidade Estadual do Norte do Paraná - UENP, Bandeirantes, PR, Brasil.
Lucas
L
Tomazella
D000818:Animals; D000871:Anthelmintics / Q000627:therapeutic use*; D005273:Fenbendazole / Q000627:therapeutic use*; D007559:Ivermectin / Q000031:analogs & derivatives* / Q000627:therapeutic use; D009611:Nitroxinil / Q000627:therapeutic use*; D010270:Parasite Egg Count; D012756:Sheep; D012757:Sheep Diseases / Q000188:drug therapy* / Q000469:parasitology
D000871:Anthelmintics; D005273:Fenbendazole; D007559:Ivermectin; D009611:Nitroxinil; C084101:doramectin