New South Wales worms, flies and lice update - August 2018

Armidale: Rad Nielsen, Veterinary Health Research (rnielsen@invetus.com)

NSW LOCAL LAND SERVICES

Central West LLS

Coonamble: Jillian Kelly, DV (jillian.kelly@lls.nsw.gov.au)

Conditions are incredibly dry. There has been no worm activity detected clinically or via worm testing (WormTests) in sheep. Faecal flotations conducted recently on mobs of early-weaned lambs all showed no worm burdens. Producers are destocking, or intensively hand feeding, and worms remain a low priority. 

Producers are reminded though to keep worms in the back of their minds when it does rain—it is expected if spring or summer rain is received that barber’s pole worm could quickly become a problem in drought affected stock.

Dubbo: Evelyn Walker, DV (evelyn.walker@lls.nsw.gov.au)

Today I saw two cases of barber's pole worm in severely drought affected Merino lambs. These lambs were malnourished, and had not been given a summer drench. A number of deaths, and only very minimal jaw swelling were observed in the affected lamb mobs.

Please remember to keep checking your sheep mobs with a WormTest even in times like this.  If rain is received barber’s pole worm will be the first to take advantage of the moisture and its ability to produce large numbers of eggs means infections can quickly impact drought affected stock. 

Forbes: Nik Cronin, DV (nik.cronin@lls.nsw.gov.au) and Belinda Edmonstone, DV (belinda.edmonstone@lls.nsw.gov.au)

There has been very little worm activity in the Forbes area in the last month due to the ongoing dry conditions. Nematodirus (thin-necked intestinal worm) is a worm that generally doesn't cause many issues, however, the egg is very resistant to dry conditions building up in the environment during these times. When it does rain, mass hatching can occur resulting in large numbers of larvae available to cause losses mainly in lambs. 

Nyngan: Erica Kennedy (erica.kennedy@lls.nsw.gov.au)

The prevailing drought conditions have reduced worm activity in sheep to almost nothing. I have not seen any clinical cases of worms since last year and have not seen any evidence of worms on faecal worm egg counts (WormTests).

There have been clinical cases of worm burdens in adult cattle, the diagnosis supported by high serum pepsinogen levels in blood tests. The tough conditions leading to suppressed immune systems are thought to be the cause of these worm burdens (Ostertagia sp.) in adult cattle. 

 

Northern Tablelands LLS

Inverell: Andrew Biddle, DV (andrew.biddle@lls.nsw.gov.au)

It’s cold and dry. And not a good season for sheep or worms.

The only interesting worm related case of late was of ewes with "bottle jaw". They had been drenched with everything, but the cause was most likely to be hypoproteinaemia due to the poor quality of the diet, and not worms.

There have also been lots of cases of pregnancy toxaemia (ketosis) in ewes. Some serious losses occurred during a cold snap a few weekends ago with mortalities of 20%. More commonly seen however, were mobs being well fed (faba beans, barley, white cottonseed (WCS), etc.) and still going down, but without showing the classic ‘preg tox’ neurological signs. Biochemical analysis identified low calcium (Ca) levels and high beta hydroxy butyrate levels. Ewes that are twinners or carrying a single large lamb are on the metabolic tightrope, and often lie down due to the weight of the lambs, low calcium levels, or low energy levels, and then can’t get up. If they are not found quickly and treated, they spiral into a metabolic crisis. This is really dis-spiriting for those producers putting a lot of money into feed and still getting losses. 

 

North West LLS

Northern Slopes: Ted Irwin, DV (ted.irwin@lls.nsw.gov.au)

Not really much to report this month.

Worm egg counts (WormTest) have shown some moderate levels of Haemonchus (barber’s pole worm) across the region, but most counts have been low to negligible. The risk of pregnancy toxaemia due to poor feed quality and quantity is also of great concern.

 

Narrabri / Walgett: Megan Davies, DV (megan.davies@lls.nsw.gov.au) and Judy Ellem, DV (judy.ellem@lls.nsw.gov.au)

We haven't seen any worm test results come across our desks recently, and presume that due to the prolonged dry, producers think that worms are something they don't need to worry about. It is true that dry times reduce egg survival in the environment, however nutritionally stressed animals are less able to cope with even low to moderate worm burdens. When you are paying for feed, you need to ensure that nothing is affecting your stock’s ability to absorb and process that feed as efficiently as possible.

We have also recently seen worm related deaths in calves (20 head lost in one mob) that were moved west from slightly greener pastures in the Northern Tablelands, so there certainly are worms about.

With many producers feeding in containment areas and trail feeding on the ground, the potential for worm spread is high. We recommend that producers do worm egg counts (WormTest) in their sheep every few months—this is easy to do when sheep are confined to smaller paddocks, and you don't need to muster them to collect fresh faeces—just follow the mob around for 10 minutes, and many of the sheep will obligingly produce samples for you to pick up. Doing a test could save a lot of time and money, if egg counts are low, you won’t need to muster and drench. The worm test and larval culture can also tell you which types of worm you are dealing with, and help you select the most effective drench—again, saving time and money. 

Doing a follow up worm test 1014 days after drenching is important to check that the drench was effective—again, this doesn't require re-mustering the moby—you can collect the faeces in the field. Don't let worms waste your valuable feed during dry times. 

Murray LLS

Albury: Mark Corrigan, DV (mark.corrigan@lls.nsw.gov.au) and Eve Hall, DV (eve.hall@lls.nsw.gov.au)and Nikita McAdam (final year veterinary student, Charles Stuart University)

Deniliquin: Scott Ison, DV (scott.ison@lls.nsw.gov.au) and Linda Searle, DV (linda.searle@lls.nsw.gov.au)

Coming into spring with rainfall below average, many producers are relying on supplementary feeding and heavy grazing of pastures to support their stock, increasing the risk of high parasite burdens. July rainfall average was 26 mm in the Albury region (Elders weather), with a past average of 70.9 mm.  Increasing rainfall this August along with increasing night temperatures will result in increased activity of larvae and egg survival on pastures.  July was similarly dry in the West (Deniliquin) with the July rainfall at half the long-term average (14.8 mm vs 29.6 mm), but unlike the East region, the current August rainfall is still well below average.  This means producers will continue to rely on intensive feeding with high stocking rates for the foreseeable future.

Of special note is Haemonchus (barber’s pole worm), which can cause anaemia and death in sheep.  A single shower of rain may be enough to induce a large number of larvae to continue development potentially leading to a severe disease outbreak unless an effective drenching and monitoring program is in place.  Trichostrongylus (black scour worm) and Teladorsagia (brown stomach worm) are also able to survive the cooler winters and therefore will be of significance on many properties.

Autumn lambs will be weaned and at this time it is important for producers to have a plan for managing parasite burdens in order to avoid weaning losses, and improve productivity.  A drench at weaning is good practice, however it would be ideal to also perform faecal worm egg counts (WormTest) prior to weaning. This can help to provide an idea on the types of worms present on farm, between mobs and paddocks, and aids in selecting the most appropriate drench. Lambs should go onto fresh pastures at weaning to prevent reinfestation.

There have been no reports of worm related clinical disease across the region, and only limited WormTests submissions, all of which showed only low worm egg counts.

 

Riverina LLS

Young: Eliz Braddon, DV (eliz.braddon@lls.nsw.gov.au)

Worm activity across the Riverina is generally light to moderate, but worm testing (WormTest) weaner/hogget sheep at the end of winter is always worthwhile.  


With the tough season being experienced, lambs need to have maximum growth rates to take advantage of feed on offer/supplementary feed and therefore be able to be sold as early as possible.  This generally means drenching by 3 months of age irrespective of whether lambs are weaned or left on the ewe.  

Because crossbred lambs have a higher tolerance to the effects of worms than Merino lambs, they will sacrifice valuable weight gain long before showing obvious signs of worm infestation. So back up the early (3 month) drench with a weaning drench when you do wean and then WormTest every 6–8 weeks.

If you are considering early weaning lambs, worm management is even more critical to ensure these lambs are moving forward at all times.  Additionally, early-weaned stock should be 'broken into' hard feeding prior to weaning to ensure positive growth.  

 

South East LLS

Yass: Fiona Kelk, DV (fiona.kelk@lls.nsw.gov.au) and Alexandra Stephens, DV (alexandra.stephens@lls.nsw.gov.au)

This month we received less than average rainfall together with multiple severe frosts and many windy days. In most places the pasture base is short and green to short and burnt off.

Worm counts this month are again variable depending on the age of the sheep tested, their drench and grazing history, and barber’s pole management on the property.

As we head towards spring nothing is more powerful as a decision making tool than a worm egg count (WormTest) and a larval differentiation (culture) from your own property. Most infections are of mixed worm types that can be identified by the worm egg count and larval culture. These are proving very valuable in determining drenching decisions. For instance, on a large number of properties barber’s pole comprised between 10 and 80% of the count. If spring rains do arrive producers need to be ready to manage barber’s pole worm on the short green pasture base.

Frequent egg counts are recommended (every 4–6 weeks) and monitoring of the daily maximum temperature and rainfall are required to keep a handle on this situation. This information will then determine the requirement to use a sustained action or short action drench

Barbervax® information sessions, occurring in the South East this week, have been proving very valuable for producers to understand all the tools they have available to manage this parasite.

The scour worm counts (Teladorsagiabrown stomach worm and Trichostongylus, black scour worm) have remained low to moderate, but monitoring of egg counts every 6–8 weeks is recommended to detect scour worms early and prevent significant production loss.

 

Western LLS

Broken Hill: Felicity Wills, DV (fliss.wills@lls.nsw.gov.au)

The drought has worsened and a lot of stock remaining in the region are being fully or supplementary fed in confined sacrifice areas.  Very few WormTests have been performed in sheep. Those that have been performed showed very low faecal worm egg counts. No WormTests have been conducted in cattle.

Producers are still being encouraged to worm test despite the ongoing dry conditions due to the increased risk of larval ingestion related to supplementary feeding from the ground for long periods, and particularly if rain falls. Our investigations of disease in livestock have been increasing as it is difficult to adequately meet the nutritional needs (Drought Feeding Calculator) of fed livestock, and any nutritional deficiencies may also increase the risk and consequence of parasite burdens.