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New South Wales worm update - January 2012

Greg Curran, VO, Broken Hill (greg.curran@industry.nsw.gov.au):

We are starting to see a surge in worm egg counts in western NSW.

A large Brewarrina flock that had worm problems last year, and is using WormTest to monitor, has shown average counts of 4000-8500epg in January, following counts of 80-1800epg in December. Culture results are not in for the January monitoring, but showed a mix of BPW, Trichs, and Ostertagia in December. Sheep were described as being in medium condition, with no scouring and no illthrift.

A submission for a small group of rams in far southwest NSW showed counts around 2000epg. Culture results not sighted yet.

Western NSW has had a series of summer rains, ranging from light to heavy. The series of lighter rains may have concentrated grazing in run-on areas.

Recent forecasts expect some very good falls in the next week, which will continue the pattern of rain, and further increase the risk of worm build up.

(The WormTest submission form doesn't provide for comments from the submitter on anaemia, which might be useful for clinicians assisting WormTest submitters, and to help submitters zero in on anaemia as a useful indicator, although it can be difficult to "get one's eye in").

LHPA DISTRICT REPORTS

Lachlan LHPA

Katherine Marsh, Condoblin (katharine.marsh@lhpa.org.au):

WormTest results in the past month have ranged from 140-884epg with an average of 381epg. Within these tests some individual results have been as high as 4000epg, indicating that worm issues are starting to become more problematic. Since there have been few requests for typing, the worms involved are not known, but with the warm, wet weather Barber’s Pole worm is likely to be a concern.

Continued monitoring is recommended. Requesting a worm type as well is also recommended to help in the selection of which drench to use. If Barber’s Pole worm is the main worm type, a drench providing sustained activity against this worm is recommended as conditions are likely to be favourable for its survival over the next few months.

North-West LHPA

Derek Lunau, Moree (derek.lunau@lhpa.org.au):

December transpired uneventfully in terms of severe clinical worm disease in sheep. Regular monitoring of worm counts has however been turning up fairly large numbers of EPG (100’s to low 1000’s). Through this process we have identified five properties that look suspiciously like there is resistance to Abamectin/Closantel combinations. On questioning producers in relation to this, Closantel containing products have often been used ad hoc and possibly some resistance brought in as well.

January has started with our first actual deaths associated with Barber’s Pole that we are aware of. One western property lost 70 lambs before it was realised. We have been actively promoting a message of worm testing and effective drenching before this occurs. January has been the month to watch. We would put this down to a combination of factors. Mostly producers had used a sustained action drench in spring (October/November). This carried a lot of places through until January. Some had re-drenched in December (based on worm counts and suspicion of some clinical disease but no deaths). Cropping means that many of our producers take their eye off the sheep for 2-3 weeks at a time, which is a perfect opportunity for Barber’s Pole if the conditions are right.

Tablelands LHPA

Jim McDonald, Yass, (Jim.McDonald@lhpa.org.au):

The Yass District is experiencing a ‘normal’ January with little rain and warm days.

Clinical evidence of parasites has all but vanished and sheep are responding well to the drier conditions.

A reduced number of worm counts have been carried out due to season.

WEC to date vary from 40-400epg with average egg counts in weaners of 100-200epg.

The area north around Crookwell, Barber’s Pole worm is the dominant parasite with larval diffs showing 90% or more BPW.

Further south, both Trichs and Ostertagia make up the bulk of larval diffs.

Looking ahead, all of the district will need to conduct a second summer drench on most, if not all, classes of sheep.

If drier conditions continue for another 2-3 weeks larvae on pasture will be dramatically reduced and give some respite from the continual worm attack most graziers have been under for 18 months.

Bill Johnson, Goulburn, (bill.johnson@lhpa.org.au):

Worm larvae on pastures have had another dream run this summer. It has not been hot or dry enough for long enough yet to kill many worms on the ground. And apart from only a few areas to the south of town, most of them are also sheltering in the shade of long, dry grass. We should be better prepared for worms this time, as the story so far is very similar to last summer.

Merino weaners and store crossbred lambs very rarely made it onto low worm pastures, and worm egg counts indicated they needed a second drench by mid-January. Scouring has been minimal, despite most of the worm burdens being combinations of Nematodirus and the BSW twins.

Most sheep owners have been quick to recognise the signs of Barber’s Pole worms this time. They are being seen in both lambs and adult sheep for the third autumn in a row. If sheep tire easily, have pale skin, or maybe fluid swelling under the jaw, a high worm egg count will usually confirm the suspicion. One recent worm egg count in ewes did just that, with the 8000epg being identified as 100% Barber’s Pole!

Barber’s Pole worm resistance to longer-acting drenches is becoming more common here, with both the Moxidectin injection and Closantel-based products affected. We still have some way to go before we catch up to the situation in the New England, but we can no longer simply rely on the stated protection period for these products against Barber’s Pole worm. The only safe bet is to monitor by worm egg count and culture after drenching, during the expected protection period.

Take the opportunity to box dry ewes into bigger mobs after drenching, and rotate them through paddocks to be used later for lambing. The higher stocking rates will help knock down old pasture, exposing worm larvae and encouraging clover germination and pasture regrowth.

And if running sheep is getting too difficult, spare a thought for this hapless goat owner: The Boer goats had a worm egg count of 10,800epg - twelve days after drenching with the most effective drench currently registered for goats! You can always find someone worse off than yourself…

Central West LHPA

Evelyn Walker, LHPA DV, Dubbo (evelyn.walker@lhpa.org.au):

Barber’s Pole worm continues to rear its ugly head this summer and is taking its toll particularly in young sheep. Seasonal conditions in the Central West area have seen Barber’s Pole worm re-infection anywhere from 4-6 weeks after drenching in young sheep. It is common knowledge to drench and move sheep to a clean paddock, but what is the definition of a “clean paddock” for the Dubbo area?

As a general rule, I tend to recommend that a paddock should be spelled at a minimum of two hot summer months (average temps of 22-25 degrees Celsius) or 3 months ideally. A paddock is NOT considered clean after one month with grazing cattle on it. Although many producers are being diligent with using effective drenches, a few have been caught out with only using short-acting drenches to combat Barber’s Pole worm. For most susceptible sheep (e.g. weaners) and depending on your WormTest results, using drenches with sustained activity against Barber’s Pole may be a good option for some to get you through the Barber’s Pole season.

After drenching, monitor your egg counts over the next couple of months using WormTests to gauge whether a drench is necessary. When finishing lambs, a shorter acting broad spectrum drench may be a viable option for some. If in doubt, check with WormTest and do a post-drench check 10-14 days later to make sure the drench you’re using is effective.

Riverina LHPA

In the East, based in Narrandera, Gabe Morrice reports she has had no WormTests come in over the last few weeks. Gabe says she has been to two clinical cases; the first case was in 3 month old lambs with serious ill thrift and scouring caused by Nematodirus. The second case was in purchased Dorper ewes on irrigated pasture where the owner has lost 3 ewes and looks like Haemonchosis.

In the West, based in Hay, Colin Peake says that he has received very few WormTests in the last month. They have either been negative or very low and only 1 test with an average of 388epg (range 80-960), for strongyles and average 356epg (range 40-680), for Nematodirus in merino weaners. It has been hot and dry in the western Riverina, so larval recruitment should be low this summer.

In the south West, based at Deniliquin, Dan Salmon reports he has been receiving a few WormTests in which have all been negative or close to it.

These are mostly sheep which were drenched in the late spring or early summer with MLs.

This gives Dan a little hope that recruitment over the summer has been low and that ML resistance is not as bad as it might be.

Hume LHPA

Ian Masters, Gundagai, (Ian.Masters@lhpa.org.au):

Weather has turned hot and dry. Pastures have hayed off in most areas so we might finally get a break in the worm cycle. A lot of monitoring carried out this month with considerable variation in results. In general worm burdens in adult sheep are not too bad but reinfestation following drenching in Nov/Dec in young sheep has been a problem. FEC’s of 2-3,000 in young sheep that were drenched with a triple combination drench in late November /early December are not uncommon. In most of these cases sheep went back onto the same paddock after drenching. Scouring and deaths have been seen in some mobs. Trichs and Ostertagia are involved in most cases but there are flocks in the higher rainfall areas with 10-15% Haemonchus on differential counts so it would be wise to monitor these flocks next month to determine the need for a follow up summer drench.

South East LHPA

Bob Templeton, Braidwood (bob.templeton@lhpa.org.au):

The worm population is a mixed bag at present. Some flocks are experiencing an early Barber’s Pole worm infection with associated losses. However, nearby flocks have a mixed population of small Brown Stomach worm and Black Scour worms. While other flocks are relatively free from worms. It looks like the Barber’s Pole problem will only get worse as the season progresses.

The green cool summer has seemingly ended with pastures finally haying off. However, the regular rain events have led to a high level of contamination of infective larvae in most pastures. With this in mind, the use of a drench with an extended period of action would be advisable. This would be best done after a WormTest to see which worms are involved.


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