Perry Parkinson - Strategies to reduce anthelmintic resistance
Perry was announced as a winner of the NSA Samuel Wharry Memorial Award for the Next Generation in late 2022, to plan travels and write a report in 2023 and 2024. He filed his report and did a presentation at the NSA Sheep Event in July 2024.
Travel overview
Anthelmintic resistance was the focus for Perry’s trip to New Zealand where he spent a month with farmers and industry experiencing the effects of resistance on a much larger scale than here.
Perry is a first-generation farmer managing his own flock of commercial ewes on arable and grassland in Stirlingshire. He is particularly interested in anthelmintic resistance and through breeding, improved animal health plans and regular faecal egg count monitoring, his future aims are to lower and potentially remove the need for anthelmintic use and be more sustainable in his flock management.
His research assessed the current UK methods of sustainable parasite control and investigated innovative methods in New Zealand, such as breeding strategies, testing regimes, treatment choices and alternatives to anthelmintic use such as grazing strategies.
“Seeing real life resistance issues coming into the diagnostics lab really put into perspective how big the problem is over there,” says Perry. “With a lot of samples showing egg counts in the thousands, it was definitely a reality check.”
He visited farmers already using faecal egg counts along with grazing rotations, cropping choices, genetics and hard culling regimes to combat issues with anthelmintic resistance and other parasite challenges, but was sad to learn this level of awareness wasn’t always the case.
“Farmers are generally very negative and see taking faecal egg counts as a chore,” says Perry. “They would rather gather their stock every three weeks to worm just to be sure. But this attitude doesn’t look to the future when it comes to resistance and refuses to see the overall benefit of monitoring.”
He would encourage farmers to adopt faecal egg count principles so they become the norm. Another surprise during his New Zealand trip was the advice given from vets, which he says is contributing to a rise in resistance.
“Because vets sell anthelmintic drenches to farmers, there is a monetary gain from their perspective so large quantities are sold alongside hampers at Christmas and Easter. Vet advice in New Zealand is to triple drench then repeat 24 hours later. I find this shocking when the level of anthelmintic resistance facing New Zealand farmers is so high. Triple drenches are effective in New Zealand but it’s a vicious circle as overusing them without rotation will reduce their efficacy.”
He explains newer wormers such as orange (group 4-AD) and purple (group 5-SI) are helping reduce worm burdens in New Zealand, but there are concerns their effectiveness will start to fall if not used correctly.
He concludes: “My take home message is do a faecal egg count, see how simple it is and how much beneficial data it can provide you. What have you got to lose?”
Full report
Download Perry's report for detail on his travels and findings.
