Anthelmintic resistance in Swedish laying hen farms

Last changed: 29 August 2022
Illustration Ascaridia galli

Because of the implementation of the EU directive 1999/74/EC, the occurrence of Ascaridia galli (A. galli) has dramatically increased within the past decade in commercial laying hens in some European countries including Sweden. This situation has led to a significant increase in the frequency of anthelmintic use in laying flocks.

The extensive use of anthelmintics to control helminth infections is generally known to be a contributing factor to the selection for resistance against these drugs. Resistance to all major classes of anthelmintics has been reported worldwide, especially for BZs in gastrointestinal nematodes of ruminants.

Our recent field observations have shown that certain flocks remained positive for roundworms despite the administration of anthelmintics (AH). This among other explanations can indicate treatment failure as a result of the development of anthelmintic resistance (AR). This poses a growing threat to the egg industry and negatively affects birds' welfare and productivity.

Aim: to investigate the development of AR in Swedish laying hen farms by examining samples collected from farms with signs of reduced drug efficacy. You will also have the possibility to examine samples from flocks with multiple exposures to AH and look into possible genetic changes due to repeated exposure.

Methods: novel molecular diagnostic tool based on droplet digital PCR and DNA sequencing to identify genetic changes in genes associated with AR. This includes DNA extraction, performing ddPCR, and data analysis.

Time frame: flexible. Suitable for 30hp project


Contact

Johan Höglund
Professor at the Department of Biomedical Science and Veterinary Public Health; Parasitology Unit

Telephone: 018-672371, 070-2574156
E-mail: johan.hoglund@slu.se