WRML. WormFaxNSW-July and August issues are on-line / WormBuster lab report (QLD).

July-August wormbuster lab newsletter.pdf Download this file

To WormMail list (recip. undisclosed).

July and August issues of WormFax are now online.


(Many thanks to Kath Cooper and colleagues (State Vet Lab., DPI), Veterinary Health Research, Armidale, and Craig Bratby (Web Services, DPI)).

If you cast an eye over these WormTest results for various districts in NSW, you will see that there are some sheep mobs with high egg counts, e.g. several thousand or more epg.

These are often but not always mostly found to be Haemonchus when larval culture are done.

You might wonder why there are mobs of sheep with quite high worm egg counts after a few months of winter.

We know for example that Haemonchus (barber’s pole worm) eggs do not hatch and develop through to third stage (infective) larvae to any great degree when overnight temperatures are consistently below 10 degrees.

Similarly for Trichostrongylus colubriformis (one of the species of black scour worm), although its eggs are a little more cold and desiccation tolerant than Haemonchus. (The eggs of Trichostrongylus vitrinus (found more in winter rainfall areas), and Teladorsagia, are even more cold tolerant).

So, why are sheep still getting high egg counts towards the end of winter?

Here are some possible reasons:

* lots of infective larvae on pasture from autumn

We have had two ‘La Nina’ years (above average rainfall) in a row, so pasture infectivity has been high in many districts of NSW.

For worms like Haemonchus and Trichostrongylus, the infective larvae are much hardier than the eggs.

Haemonchus eggs for example only live for five days or so. However Haemonchus infective larvae last for months under cool to cold conditions. (Cold by Australian standards).

* use of ineffective drenches

Resistance of the important sheep worms (Haemonchus, Trichostrongylus, Teladorsagia (brown stomach worm)) to most drench families is generally very common.

Producers who know exactly (by testing) how effective the drenches are on their farm are relatively uncommon. (We’re all human)

In short, the unwitting use of relatively ineffective drenches is pretty common.

The most expensive drench is the one that does not work.

* lack of monitoring

Clearly many producers do not monitor worm burdens by way of worm egg counts ("WormTest") frequently enough.   Perhaps some of these with high egg counts were only monitored because clinical signs of parasitism had appeared.   By that time, production losses are substantial.

Worms, the ‘quiet achievers’, are largely invisible:

* they themselves are mostly hard to see

* the losses they cause are largely invisible (unless deaths occur, .e.g. haemonchosis)

* resistance of worms to drenches is largely unnoticed until there are control failures (clinical parasitism)

Don’t guess, WormTest.

For those in Queensland (or anywhere else really)….

As a special treat, attached is  the July-August issue of the WormBuster lab report, produced by parasitologist Maxine Lyndal-Murphy.

Although of direct relevance to those in or near Queensland, it is also of general interest to anyone interested in sheep worm control.




WRML: Managing goat worm challenges Ag Today Sept 2012 / The basics of sheep and goat worm control / do you smell? / LHPAs and Sheep Scab

20120919142845.pdf Download this file

And a slightly modified version (sans the minor glitch in the goat only article in Ag Today).

Managing worms in sheep and goats-the basics

Bernadette York/Stephen Love

WORM management for goats requires extra attention to detail according to NSW State Worm Control Coordinator, Stephen Love.

“Goats carry the same worms as sheep and some cattle worms – the big three affecting goats are barber’s pole, black scour and small brown stomach worm,” Dr Love said.
“The principles of worm control are generally the same as for sheep, but there are additional challenges when it comes to worm control in goats.

“Goats are usually more susceptible to worms than sheep.

“This susceptibility can be partly ameliorated by their tendency to browse shrubs where they miss most of the infective worm larvae which occurs in the bottom 10 centimetres of pasture.

“As with sheep, resistance of worms to drenches is very common and compounded by the lack of registered drenches for goats.

“Goats tend to metabolise or eliminate drenches faster than sheep, which means goats often need a higher dose rate than sheep to achieve the same effect and with some drenches this can be a safety issue.

“Drench resistance may be due to goats being treated more often, perhaps because they need more frequent treatment, especially if lacking in browse, and because drenches may be more commonly given at less than optimal dose rates.

“It may also be the case that goats from different areas are traded more often, with the result that resistant worms from one area spread more rapidly to other areas.”

There are six very important details to address in order to achieve effective worm control in goats as well as sheep:

1.        Don’t import resistant worms – when buying goats or sheep from other properties, make sure they get an adequate quarantine treatment. This will mean a combination of unrelated broad-spectrum active drenches. A drench for liver fluke may also be required.

2.        Do regular worm egg count monitoring, WormTest, to see if drenching is required or not. Don’t guess, WormTest.

3.        Check the effectiveness of drenches, with a WormTest on or just before the day animals are drenched, followed by a WormTest 10 days later (DrenchCheck Day10).

4.        Consider using combinations of broad-spectrum drenches rather than single active drenches. This doesn’t necessarily mean mixing different drenches in the same drum (which in some cases may be ill-advised). It may mean drenching with one product, followed immediately by another.

5.        Animals with good genes and good nutrition cope much better with worms.

6.  Use grazing management (e.g spelling, rotational grazing using cattle) to reduce  exposure of animals to worm larvae

In NSW drenches registered for goats include broad-spectrum drenches, benzimidazole (BZ) or ‘white’ family drenches, one drench with abamectin from the macrocyclic lactone (ML) group, one drench with morantel in the levamisole-morantel group and flukicides containing triclabendazole.

Off-label usage of drenches requires advice on the safety, efficacy, dose rates, withholding periods and prescription from a veterinarian.

Contact: Stephen Love, Armidale, (02) 6738 8519 or stephen.love@dpi.nsw.gov.au

(Content: S Love. ‘Wordsmithery’: B York).

Do you smell?    đŸ™‚


History of sheep scab (Australia)

This is interesting:   http://sydney.edu.au/vetscience/avhs/milestones/sheep.pdf

I believe Livestock Health Authorities in NSW have their origin in sheep scab eradication in NSW in the 19th century. (Something not yet achieved in some other countries).

For most of their history, LHPAs were known as Pastures Protection Boards and, for a while, Rural Lands Protection Boards.