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New South Wales worm update - August 2013


Lachlan LHPA

Belinda Edmonstone and Nik Cronin, Forbes (  (

In the central area of the Lachlan LHPA there were 22 worm test performed for the month of August with average faecal egg counts ranging from 0-1120. Individual counts range from 0 – 7120. There have been some high counts in Nematodirus eggs on some of the worm test performed on weaner lambs. This worm producers eggs that are very resistant to dry times. When it rains they can then hatch in large numbers and if picked up by lambs will cause scouring, ill thrift and death. Weaning time is an important time to drench lambs with an effective drench onto a clean paddock.

Kasia Hunter, Condobolin (

In the western area of the Lachlan LHPA only one WormTest was conducted during the past month. The average faecal egg count was 100 Strongyle eggs per gram (range: 40 – 160), with no Nematodirus eggs detected at all. The larval differentiation demonstrated that the parasite burden consisted of 99% Haemonchus (Barber’s Pole Worm) and 1% Ostertagia (Small Brown Stomach Worm). No parasite related health issues have been reported or observed, however with ongoing rain across the area parasites may become a problem. Producers are encouraged to consider conducting a WormTest if unsure of the status of their sheep.

Elizabeth Braddon, Young (

Pre-lambing ewes are the group that is most being tested in the Eastern part of the Lachlan LHPA with 17 tests being done this month.  The average across all classes was 158 epg (but the weaners were running at about 89 epg and the ewes about 180 epg) however, the range was 20 – 360 epg so the variation between tests was quite high.  Interestingly we are starting to see Haemonchus creeping into these counts in quite high percentages (eg. one test with a mean of 292epg had a 96% population of Haemonchus).  So that causes concern for a rapid increase in Barber’s Pole (Haemonchus) activity with spring temperatures rather than the usual month or two to get enough build up of numbers;  combine this with the fact that we know approximately 50% of the properties have some level of Mectin drench resistance in this species and we are heading for a challenging spring. 

So if you don’t know the status of your drenches and you haven’t done any larval cultures to determine which worm species are active, this would be highly recommended for this year to ensure drench choices are based on the best information possible.  With the amount of ground cover and the moisture levels at that level, the micro-climate for Haemonchus is going to be ideal and that means it will take at least 3 months to really clean up a paddock.  The same will apply for our usual scour worm populations, so if you haven’t got that amount of time to spell a paddock, you need to be vigilant for worms.

Central West LHPA

Evelyn Walker, LHPA DV, Dubbo (

Although there have been few worm test reports received this month from Dubbo and surrounding areas, there is still definite worm activity present. Worm burdens (ranging from low to medium) and worm type have varied from farm to farm. On some farms the major worm type is Barber’s pole worm and on others, the predominant worm type is Black Scour worm. This month, I have investigated multiple deaths in lambs due to heavy Black scour worm burdens. If scour worms are left untreated for too long, affected sheep will die from severe dehydration and malabsorption. So don’t forget to monitor your mobs now with a worm test.

Tablelands LHPA

Bill Johnson, Goulburn, (

Compared with the rampant losses from worms the previous two winters, most sheep flocks are faring pretty well this year. Summer drenching programs have been effective at reducing burdens of black scour and brown stomach worms in weaners and lambing ewes. About half the mobs monitored have very low worm egg counts, despite being months since drenching.

Barber’s pole worms continue to be the major worm species on about one third of properties. It is important to know whether they are present in your flock, and at what level, prior to spring. These sheep aren’t crook, and they don’t flop down when you move them briskly across the paddock (at least not because of worms, anyway). The only way to know you may be sitting on a barber’s pole time-bomb is to ask for a worm culture when you send off a wormtest.

There have been a few worm crashes, mainly in lambing ewes. But in all cases, a lack of adequate tucker played a major part. Brown stomach worms have been the main offender.

And don’t forget about the possibility of liver fluke in stock which graze paddocks with flowing creeks or springs. Tests on blood or dung will help confirm their presence. August is one of the key months for fluke control. A spectacular case of liver fluke killing crossbred sheep was recently reported by Bruce Watt at Bathurst, in sheep that had been drenched six weeks earlier with triclabendazole. It appears to be a case of liver fluke resistance to this important drench type. Follow up your next fluke drench with a dung test to ensure it has worked.

South-East LHPA

Bob Templeton, Braidwood, (

The wet winter around Braidwood/Bungendore has dished up some very interesting results.  A mob of heavily pregnant merino ewes return an average of 300 epg but with a 94% Haemonchus!  Other flocks are also showing signs of haemonchosis.  This is strange after a very dry autumn.  We now await the onset of spring with some concern.

Petrea Wait, Cooma. (

In the Cooma and Bombala regions our producers are still running Wormtests on a regular basis. Mostly these are on pre-lambing ewes or on weaner mobs that are not doing as well as expected. Counts have been relatively high ranging from 300epg to 1500epg in lambing flocks, with a count of 6000epg from a very sick weaner. The scour worms seem to be the predominant species, Trichostrongylus mainly but also some high counts of Oesophagostomum. We are also seeing liver fluke eggs in a number of the tests run so it will be important for producers to test and drench for these before Spring.


Tony Morton, Wagga Wagga (; Amy Shergold, Wagga Wagga. (

Worm burdens have been variable around Wagga Wagga this month. We have seen worm tests done on lambing ewes, hoggets, weaners and lambs at foot. While some mobs had very low counts, others had significant infestations with small brown stomach and black scour worms. Larvae of these species are surviving well this time of year and pasture contamination has been a problem. Despite the cool conditions, barber’s pole worm has been identified in a couple of mobs with mixed burdens. This species was also seen in the abomasum of a weaned lamb at autopsy, which was an incidental finding.

There have been some high counts in lambs between marking and weaning. If you have lambs at foot that are showing illthrift, scouring or not growing well, worms should be considered. Other recommendations this month include continued faecal monitoring every 6-8 weeks following a drench and weaning lambs onto ‘clean’ pastures.

One farm in our region had an average count of 384 epg in weaners (range 80-920 epg) following an effective drench in July, reflecting larval contamination of the pasture. There was a tail of the mob that looked illthrifty and approximately 5% were scouring. A subsequent drench was given; however 90 head were left undrenched and we performed a drench resistance trial on these animals. We are waiting on the results, which will tell us which drenches are effective on this property and which are no longer working.

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