Imagine a day when you have worms in your lambs, they are dying and you have no way to treat it... it’s happening... and it poses a huge threat to farming as we know it.


It’s been spoken about for along time and a lot of us haveburied our heads in the sand and denied that it could ever happen to us. It’s happening in the Maniototo and after speaking with vets from all over the country at the NZVA conference I am assured that it is happening nationwide, in much higher numbers of flocks than we expected, in ALL sheep breeds, and to “good” farmers. This is a big deal, and we need to start being proactive now to prevent this from ruining the future of sheep farming in the Maniototo.

Why is this happening?

Every time we drench an animal, some super-worms may survive, its natural selection. Those worms are now resistant to that drench and will continue to produce eggs, which will then go out onto the pasture in the faeces and create a resistant worm population on your farm. Chances of a worm being resistant to a triple active drench are much lower than to a single active drench – BUT these super-worms do exist!The amount of exposure to a certain drench a worm population has will also affect the chances of resistance, this is why new “novel” active drench families (eg. Zolvix Plus) work so well at the beginning…BUT as time goes on and more worms are exposed to these actives, super-worms will survive. So resistance happens, and when it does that drench will not kill all the worms anymore.

What can we do about it? Know your enemy. We cannot manage what we do not measure.

  • Check your drenches.
  • Get a FEC done 10 days post-drench, every time you drench, to ensure no worms are surviving
  • Get a FECRT done.
  • Only 2% of our sheep farming clients in Ranfurly got a FECRT done this season and this is a consistent figure over the last 3 years. This is not good enough; every farm needs to get one done.
  • Repeat your FECRT at least every 3 years
  • It is not enough to have done it once, you need to monitor it. Do not become complacent.
  • Drench appropriately and effectively
  • Don’t drench if you do not need to, and if you do drench, then do it right!
  • Don’t rely on drench.
  • Utilise other worm management strategies in your farming practice e.g. nutrition, refugia, cross-grazing, genetics and feeding crops

Bottom line is triple drench resistance is here! You need to know what resistance you have on your farm – please do not bury your head and think this will not happen to you! Capsule season is coming up; these products are very high risk for developing drench resistance – all capsule decisions should be made after discussions with your vet. Let us help you reduce the risk on your farm! Talk to your vets, monitor your farm and improve your drenching.

08 August 2018, 21:07