Queensland worms, flies and lice update - January 2019

Brisbane: Maxine Murphy, Veterinary Parasitologist (maxine@paraboss.com.au)

The ongoing extreme heat and dry weather have long since sealed the fate of worm eggs and larvae in paddocks. But, as most sheep do carry a few worms, eggs are continually being expelled, keeping the potential for ‘worms’ always present.

Summer storms, i.e. a bit of rain, but nothing much, while not drought breaking do signal danger. They can provide, in less hostile environments at least, conditions suitable for worm development, if only for a few weeks, giving time for eggs to hatch into infective larvae and grass to grow green shoots. In less drought-affected regions, heavy dews over a few days could also provide sufficient moisture.

Worms easily establish in young weaners, especially when they are nutritionally stressed, as they compete with the host for nutrition. Further crowding onto areas of green pick rapidly increases the level of contamination there and the situation escalates.

If the weather dries out again, it is easy for producers to assume that the worm issue no longer exists. However, this is not always the case. Stock needs to be monitored four weeks after any rain, and definitely two–four weeks after any follow-up rain.

Do WormTests, and while you are in the paddock collecting the samples, also check the sheep. Look for any that are lagging or separate from the mob, or are lethargic and lying down.

If on closer inspection, these sheep have pale gums, and pale membranes that line the inside of the eyelids, then a drench to the whole mob is indicated.