[Anthelmintics resistance in gastrointestinal nematodes in domestic animals].

The research article discusses the issue of anthelmintic resistance (AR) in domestic animals in Belgium and parts of Europe, identifying the prominent nematode species employing this resistance and discussing possible control measures to delay or avoid the development of resistance.

Anthelmintic Resistance in Belgium and Europe

• The article reveals that Belgium has reported benzimidazole resistance in 28% of the sheep farms and 29-50% of the studs. The prevalence of anthelmintic resistance (AR) in some European Union states is higher than in Belgium, while it is nearly non-existent in some Southern European countries.
• AR is widespread in certain nematodes of sheep, goats and horses in Europe, but there have only been sporadic instances of AR in helminths of cattle. In Belgium, there has been one reported case of AR in goats and one in cattle.
• There have been no surveys conducted on pigs for AR in Belgium.

Nematode Species Exhibiting AR

• The primary helminth species in which AR has been observed are the Haemonchus contortus, Ostertagia circumcincta and Trichostrongylus spp. in small ruminants. For horses, the Cyathostominae are the major culprits and for pigs, it is the Oesophagostomum spp.

Resistance Development

• Resistance has majorly developed against the benzimidazoles and to a lesser degree against the levamisole/morantel group.
• The prevalence of ivermectin resistance is currently low, but there has been an increasing number of cases in recent years.
• The actual prevalence of AR is likely higher than reported due to the low sensitivity of the currently used techniques for AR detection, such as the egg count reduction test and in vitro egg hatch test.

Control Measures to Avoid Resistance Development

• The research article concludes by discussing potential control measures that could be employed to either prevent or delay the development of resistance.