Lamb Production

Barber’s Pole worm warnings in NSW after Dubbo sheep deaths

Sheep Central November 21, 2016
Barber's Pole worms in a lamb's abomasum are red due to feeding on blood.

Barber’s Pole worms in a lamb’s abomasum are red due to feeding on blood.

NEW South Wales sheep producers are being urged to plan to counter Barber’s Pole worms in their flocks due to continuing warm, wet weather across the state.

Central West Local Land Services is encouraging sheep and goat producers in Dubbo and surrounding areas to check their mobs for worms.

Worm egg counts have been exceptionally high this month, with on farm losses due to Barber’s Pole worm (Haemonchus contortus) occurring in young animals even on their mothers.

Dr Evelyn Walker of Central West Local Land Services said LLS officers have noticed an increased number of deaths and ill-thrift due to Barber’s Pole worm in the Dubbo area. Click here to get Sheep Central story links sent to your email inbox.

Weaners are also highly susceptible

“Contaminated pastures from mild winter conditions coupled with current warm wet weather have been conducive for rapid larval build up in paddocks,” she said.

In the October ParaBoss state outlook, several LLS veterinarians recommended producers monitor worm egg burdens with WormTest to help develop their management and drench strategies. Conditions are regarded as favourable for Barber’s Pole worms around Narrabri and Walgett.

Central West LLS veterinarian Dr Jillian Kelly at Coonamble said recent rains and warm temperatures have seen a significant increase in barber’s pole worm burdens.

“No clinical cases have been seen, but counts of 12,000 eggs per gram in individual sheep have been seen, and mob averages are commonly in the thousands.

“Interestingly, producers who have been proactive in their worm management and who have been worm testing and drenching strategically over the past few years, still have low burdens,” she said.

“Properties with the highest burdens seem to have used unmanaged sporadic worm test/drenching strategies.

“A good lesson can be found in this — WormTest and drench only when necessary.”

Barbervax vaccine demand expected to be high

Armidale DPI veterinarian Dr Steven Love said a lot more people will be considering Barbervax, at least in young sheep, including those in central and southern NSW which have been seeing higher numbers of Haemonchus, a situation which is a regular occurrence in the north east of NSW, ‘Haemonchus heaven’.

“If it is at all possible, prepare a low-worm risk paddock for young sheep that will be weaned in mid-summer.

“It’s not too late,” he said.

Dr Love said it is critical to do regular worm egg counting, probably every four weeks while worm-risk remains high. Using ineffective drenches exacerbates worm-risk, so it is more important than ever to do DrenchChecks — a WEC on the day of drenching and again 14 days later (in sheep). Producers should also check the WormBoss program for their area.

No reports of mortality due to Barber’s Pole had been received in October.

Western Australian veterinary parasitologist Brown Besier said Barbervax vaccine sales are up on last year and production has been increased ahead of anticipated stronger demand.

“One issue is that vaccination really needs to start ahead of the Barber’s Pole worm season, before heavy challenge develops, as immunity from the vaccine needs to be established before the sheep meet big numbers of Barber’s Pole larvae.

“It will be important that given the relatively early start to the Haemonchus season, anyone wanting to start from scratch from now onward follows the guidelines, especially making sure that sheep aren’t grazed on paddocks heavily contaminated with Barber’s Pole worm until the third vaccination – this takes some planning, and would be best done by talking to an adviser to estimate the likely risk situation with various paddocks.”

Barber’s Pole worm dominates results

North West LLS veterinarian Justine McNally at Moree said results from worm testing during September and October were dominated by black scour and Barber’s Pole worms.

“We have unbelievable amounts of feed up here at the moment and pasture stands are still high.

“Sheep with low to medium level worm egg counts should be moved on to clean pastures to avoid grazing low and picking-up worm larvae.”

South East LLS veterinarian at Goulburn Bill Johnson said abundant high-quality spring pasture was keeping worm egg counts in check in October, but some mobs of hoggets had needed a drench due to a recent build-up of brown stomach and black scour worms. Monitoring had shown Barber’s Pole worms at significant levels in other flocks.

“It is likely the optimum timing of the first summer drench will be delayed by a couple of weeks this year due to weekly showers keeping pastures green,” Dr Johnson said.

In October, Central Tablelands LLS veterinarian Nigel Gillan said WormTest results from the Mudgee district in the past month have been mixed, ranging from very high egg counts (100 percent Barber’s Pole) to very low counts.

“In one case, diarrhoea and weight loss were reported in a mob with a negative worm egg count—this is a reminder that not all cases of scouring are due to worms.

“Current warm, wet conditions will favour the development of barber’s pole larvae on pasture, so monitoring of egg counts is wise.”

Start worm testing now

Dr Walker said the Barber’s Pole worm lives in the abomasum (the fourth stomach) where it sucks blood causing anaemia (blood loss).

Signs of anaemia include paleness of the gums, skin and conjunctiva (inner eyelids). In severe cases, the inner eyelids and gums may appear white. Some animals will display signs of “bottle jaw” — an accumulation of fluid that may appear as a swelling under the jaw and sometimes around the face.

“Flocks infected with Barber’s pole worm will experience ill thrift, profound weakness, production losses and deaths,” Dr Walker said.

“Affected animals may lag behind, collapse or die when mustered. It is therefore important when mustering these animals that they be moved slowly into the yards to avoid further losses.

“Drenching animals that are too weak to move may be required,” she said.

“Every property is different.

“So, start worm testing your mobs now to see where your egg counts are at and whether a drench is required.”

Drench resistance is a common problem in the Central West so be sure to get sound management advice.

If you would like further information about this issue please contact your Local Land Services Office or your local District Veterinarian for further advice.

Sources: Local land Services, ParaBoss. 


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