The sun has been shining and a lot of you by now have either braved a first cut, or have the clamp ready and waiting to be filled (que the rain). This being said, the emergence of this warm and damp weather should have you thinking about what parasites it may bring with it.

Silage aftermath can play a huge part in breaking the cycle of worms, therefore make good use of these fields, by using them as turnout fields for first season, unvaccinated grazers. The better the immunity build up for heifers within the first 2 years, the more productivity within your herd, and reduce the need to use anthelmintic products in the milking cow.

Key factors to consider right now:

  • Nematodirus
  • Blowfly strike/ nuisance flies
  • Lungworm risk


Warmer temperatures of 10 degrees or more, after a cold snap can trigger the hatching of Nematodirus eggs on pasture that was used for ewes and lambs last season. This usually coincides to when lambs are just old enough; approx. 6 weeks, to be increasing their intakes of grass, leading to a huge uptake in these eggs. This worm has a different lifecycle to the standard worms seen in sheep and can cause sudden death in lambs as well as stunted growth, so being prepared is key. Recommended treatment for Nematodirus is a white (1-BZ) drench, but always know what you are treating for by submitting faecal samples into the practice.

Blowfly strike/nuisance flies

We often treat for flies when we see the problem develop; strike within sheep and cattle being bothered. We need to step in before this happens and begin preventative measures before seeing a real problem. Reducing the build up of flies from the start of the season will see us through a better year.
There has already been reports in the area of strike in ewes, so pour on applications around this time are worth considering. There is options to suit all withdrawal requirements in lambs, so please get in touch with any questions.

Nuisance from flies to the dairy cow can also effect yields and health so fly prevention is critical to keep the herd consistently happy. Again, pour on applications and flectron tags are available as well as the biological fly parasites. These are all offered through our VetTech service, so enquire to discuss any of these options.


We do hope that by this time we have got all youngstock vaccinated with Huskvac and happily outside. A huge risk to our cattle in summer can be lungworm as it can cause long term damage and sometimes sudden death in animals. We see lungworm larvae build up start from June onwards in typical years, and the 1 week interval in which the larvae hatch and develop makes it very critical to diagnose and treat as soon as we suspect a problem. First season grazers are the most ‘at risk’ animals. Immunity has to be built up within the first two grazing seasons to enter a cow into the milking herd, that has had enough exposure to become immune.

Always remember that we should not be turning out first season, vaccinated heifers onto ‘clean’ pasture (silage aftermath). The Huskvac vaccine works best by exposing the animals to a small amount of lungworm.

BUT, if not vaccinated, clean pasture is critical at turnout.
If you feel there is a problem within your herd with lungworm, we can offer a parasite control plan tailored to your farm, which can focus on building that immunity effectively, and reduce the use of anthelmintics, as well as improving cow health and longevity.

Key worming factors