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Australia's resource for control of worms, flies and lice in sheep,
and worms in goats


Southern Qld/Northern NSW, Southern coastal NSW

Protracted rain events with high cumulative rainfall are forecast for some areas.

Check your 10-day forecast.

Many of us are now dubious about rain forecasts, thinking "I'll believe it when I see it". As such, there is no certainty to whether these conditions will come to pass.

Let's hope that everyone gets the rain they want, but not enough to cause devastation. 

If your area is at risk, you might consider these precautionary actions:

1. If not too late, susceptible sheep could be treated with flystrike prevention now, particularly for body strike, which will be more likely under predicted high and prolonged rainfall. Drenching may be warranted under some conditions, see details below map.

2. Move livestock to safer locations:

  • High away from potential flood risk
  • Maximum shelter to reduce exposure risk
  • Accessible to bring fodder and check sheep for flystrike

Read more below the map.

8-day rainfall forecast. Source: Bureau of Meteorology
8-day rainfall forecast. Source: Bureau of Meteorology

The map above, from the Bureau of Meteorology, shows a total forecast rainfall for the period 4th to 11th February. Click this map to go to the live BOM page where you can choose a number of options to be displayed.

A year ago, in northern Queensland, heavy stock losses occurred with continuous rain. Many died from exposure.

Where possible, choose flood-free areas with trees, shelter belts or undulating country to limit the effects of wind, rain and lowered temperature.


The immediate risk will be stock lost in floods and from exposure, followed shortly by body strike if sheep are wet from heavy rain events and continued rainfall prevents fleeces from drying out. Worms will follow grass growth.

  • Spray-on flystrike preventative treatments are likely to be the fastest way to treat large numbers of stock, though an effective jetting race may be a viable option. Hand jetting will provide better protection, but will be a slower option.
  • Products containing dicyclanil, cyromazine, ivermectin or imidacloprid are likely to be the best choices for prolonged protection. As storm rain may continue through summer, the longest acting product is likely the best choice under these conditions. Read the label to ensure they are applied correctly.
    Spinosad provides shorter protection, so is not the ideal choice at this time.
  • Heavy rain can wash newly-applied chemical off. All of the chemicals need to “dry” on/in the fleece before they achieve a level of rain-fastness, even then, very heavy rain in the coming days or weeks can wash some chemical off/out of the fleece and reduce expected protection periods. Application should be delayed if rainfall is anticipated immediately after application.
  • Regardless of treatment, frequent close monitoring for flystrike each couple of days should be carried out during the high-risk period and beyond. Body strike is more difficult to see early compared to breech strike. Look for dark patches on the underline, and down from the neck, shoulder and flanks.
  • If pasture grows quickly, particularly where country is now understocked from drought, watch for chest and belly strikes in all sheep and pizzle strikes in wethers, where sheep are continually walking through longer wet grass.
  • Conditions that grow grass, grow worms. WormTest (WEC) as soon as there is green pick and continue testing each 4 weeks. Due to drought, worms may be slower to build than in other years, but don’t count on it.  Contact your lab or supplier and have the necessary kits or sampling equipment on hand.
  • Immediate flystrike protection is the current priority over drenching in most situations where stock will remain accessible for WEC testing and drenching in the coming weeks.
  • If stock currently have moderate or higher worm burdens, but will be accessible after a short time, consider drenching with an effective short-acting drench now.
  • In barber’s pole worm areas, if mustering is likely to be impossible for many weeks, drench now and consider a persistent product, such as mid-length oral closantel or long acting moxidectin injectable. Both have well-known resistance issues with barber's pole worm, therefore an effective primer drench should be given concurrently.  The ideal primer choice would be Zolvix® or Startect®, as there is very limited resistance reported with the two newer actives (monepantel and derquantel) or use a triple- or quadruple-active (Q-Drench) combination product, which have lower levels of reported resistance. At the very least use a levamisole drench as a primer. While naphthalophos (organophosphate) drench products mixed with levamisole are an excellent choice normally against barber’s pole worm and for a primer, in situations where drenching will be hurried and stock are in poor condition do not use naphthalophos products due to the toxicity risk.

Note: ParaBoss understands that people relate better to product names than to active ingredients. Therefore, our policy has always been to name an actual commercial product where it is the only one with the specific chemical active/s being referred to. Otherwise, where there is more than one commercial product for that chemical active/s we simply name the active/s or chemical group/s.