Expert Advice on Drench Resistance with Brent Neal

Brent has seen firsthand the growing impact of drench resistant parasites across different farming systems. With experience in New Zealand, Australia, and the UK, he understands that anthelmintic resistance is not just a local issue but a global challenge. Through his work as a large animal vet he focuses on helping farmers implement effective, sustainable parasite management strategies to protect productivity and prolong the efficacy of drenches.

Dr Brent Neal has seen drench resistance accelerate at an alarming rate, with clinical drench failure now a reality for increasing numbers of farmers. What was once a rare occurrence has become common, forcing farmers to rethink their approach to roundworm control.

Brent has worked with farmers who faced clinical parasitism—where drenches simply stopped working, stock health declined, and productivity declined. By incorporating all the tools available including testing, and making strategic management changes, these farmers recovered control of their parasite situation.

One client, after having triple drench resistance diagnosed, was on the verge of selling his farm. Instead, Brent advised changes to his roundworm control system—using older cattle to “vacuum” worm-laden pastures, adjusting grazing rotations, and making drenching decisions based on testing, not habit. Nine months later, his business was stronger than ever—with healthier young stock and significantly reduced drench use.

Zolvix Plus is a lifeline in cases of clinical drench failure, but it must be used wisely. Brent warns against relying on Zolvix Plus as a routine fix, comparing this approach to “throwing it around like a bottle of Sprite at a party.” Instead, he emphasises the importance of using the right drench, at the right time, based on data— not guesswork—keeping it effective for the long haul.

“We don’t want to totally petrify people—this isn’t the end of the world. The sky isn’t falling. There are ways we can work around this. But farmers need to take ownership now before the choices disappear."

Brent Neal’s advice is simple: don’t wait for the perfect plan—take action now. Farmers should talk to someone who understands their system, because even small, smart changes can have a big impact on slowing resistance.

In his view, a farmer’s approach to parasite management doesn’t have to be perfect, but a willingness to face the problem, and seeking out good information is always better than nothing. The key is to engage, ask questions, and make informed decisions rather than relying on habit

"You might not be able to do things perfectly all the time, but if you can be good all the time—that’s already better than what most are doing now."

Brent is clear that there’s no silver bullet, but by feeding stock well, managing pastures smartly, and drenching effectively only when needed, farmers can take control of the problem—before it takes control of them.