Multispecies resistance of cattle gastrointestinal nematodes to long-acting avermectin formulations in Mato Grosso do Sul.

Abstract

The use of long-acting avermectins (AVMs) in cattle to treat infections with gastrointestinal nematodes was common in Brazil until its prohibition by state authorities. The prohibition; however, was rescinded in 2015, but a scientific discussion of the pros and cons of the use of these formulations is necessary. We evaluated the levels of resistance to 1.0 and 3.5% doramectin and to 3.15% ivermectin in cattle. The worms in animals treated with 3.5% doramectin were characterized by the suppression of oviposition and by a higher proportion of adult females carrying no eggs. Haemonchus placei, Cooperia punctata, C. pectinata, C. spatulata, and Oesophagostomum radiatum were resistant to the above compositions. The administration of long-acting AVM formulations did not result in a higher efficacy against these helminth populations.

• Authors: Fernando de Almeida Borges, Dyego Gonçalves Lino Borges, Rafael Pereira Heckler, Juliana Paniago Lordello Neves, Fernando Gonçalves Lopes, Marcel Kenzo Vilalba Onizuka
• Journal: Veterinary parasitology (Vet Parasitol) Vol. 212 Issue 3-4 Pg. 299-302 (Sep 15 2015) ISSN: 1873-2550 [Electronic] Netherlands
• PMID: 26129974 (Publication Type: Journal Article)
• Copyright: Copyright © 2015 Elsevier B.V. All rights reserved.

Chemical References

• Ivermectin
• doramectin

Topics

• Animals
• Brazil (epidemiology)
• Cattle
• Cattle Diseases (epidemiology, parasitology)
• Gastrointestinal Diseases (epidemiology, parasitology, veterinary)
• Ivermectin (administration & dosage, analogs & derivatives, pharmacology)
• Male
• Nematoda (classification, drug effects)
• Nematode Infections (epidemiology, parasitology, veterinary)