AgResearch parasitologist Dr Dave Leathwick. Photo / AgResearch
AgResearch parasitologist Dr Dave Leathwick, who made a significant contribution to New Zealand’s livestock industry over his lifetime, has died.
After leaving school, Leathwick got a job with the Ministry of Agriculture and Fisheries, which introduced him to science.
In 2025, Leathwick said he was always cut out to be a scientist.
“I was never going to be anything else.”
Early in his career, he saw that parasites were becoming immune to the chemicals that farmers had been using for many years and realised this would change the way farm systems functioned.
In 1991, he joined the Parasitology team at Flock House, dedicating the rest of his working life to research that directly benefited New Zealand’s farmers and farming systems, and focused on the long-term sustainability of this country’s pastoral sector.
For Leathwick, the highlight of his career was working directly with farmers and vets, going on to real farms, dealing directly with real-world issues, and having an impact.
In his trademark self-effacing manner, he often said the only thing he had done really well in his career was to build a great team, a team that carried out groundbreaking experiments that no one else had ever done or had been able to do.
Ginny Dodunski, B+LNZ’s Wormwise Programme manager, said Leathwick’s work was his life.
She said that although he had a black belt in karate and was a keen hunter and fisherman, Leathwick was always aware of the latest international parasite science and available to help people with their work, even after he retired from full-time work last year.
Dodunski said Leathwick was one of only a handful of agricultural scientists in New Zealand whom farmers would contact directly, and farmers appreciated his understanding of the complexity and practicability of farm management as well as his in-depth knowledge of parasites.
“Dave was always so accessible, he was frank, and people knew that what he told them was what they needed to hear – not necessarily what they wanted to hear.
“He never sugar-coated anything.”
In one project, Leathwick, along with another parasitologist and a farm advisor, identified farms with multiple drench resistance and worked alongside the farmers to help them apply what had been identified as best-practice parasite management.
The farmers who followed their advice improved their drench resistance status, but the project also reinforced to Leathwick the importance of ensuring farmers knew they were being respected as experts about their farms and farm systems and weren’t being dictated to by scientists
For Dodunksi, Leathwick’s passing didn’t just leave a hole – it left a chasm.
“If I had to name the one person who was most helpful to me [as Wormwise programme manager], it was Dave.
“In particular, his willingness to contribute to Wormwise’s online vet discussion forum and the time he took to put together comprehensive answers to often difficult questions.”
Leathwick’s expertise in anthelmintic resistance was recognised both nationally and internationally.
In 2010, he received the McMeekan Memorial Award, recognising his leadership in understanding and managing drench resistance.
In 2023, he was named Primary Industries Champion at the Primary Industries New Zealand Awards for his “unwavering commitment to the rural sector”.
Dr Dave Leathwick died on December 27, 2025.
B+LNZ and Wormwise said they wanted to send sincere condolences to Leathwick’s family, friends and colleagues.
– Supplied by Beef + Lamb NZ