test for macrocyclic lactone cattle ‘pour-ons’ at 14 days post-drench?? ……. was, Re: cattle drenches, resistance and rotation – a conversation…….

To: WormMail list  (cc LOs; QAAH-L)    WormMail 201005261015

In the previous WormMail (see below), I suggested cattle producers in Australia should check their drenches (‘DrenchCheck’) from time to time by doing a ‘WormTest’ (faecal worm egg count) 7-10 days after treatment.

The reason for  waiting at least 7 days is to allow for gut transit time (time for eggs in the gut at the time of treatment to pass out in the dung) and to make an allowance for ‘egg lay suppression’ (It is known that some anthelmintics can cause female worms to temporarily cease laying).

The reason for the upper limit – 10 days (14 days for sheep) – is the prepatent period of various worms of interest, which, as a rule of thumb, is around 3 weeks.  By prepatent period we mean the time from when the host ingests infective worm larvae until those worms mature, reproduce and pass eggs in the faeces.

In cattle, some Cooperia(small intestinal worm) can have a prepatent period as short as 11 or 12 days. Hence 10 days post treatment as the upper time limit for testing.

But nothing is perfect, and there are various complications.

Paul Mason, well known parasitologist from New Zealand, made this comment:

Post drench testing is fine and laudable, and testing 7-10 days after
treatment with an oral anthelmintic is OK.  But it is not so simple with
a pour-on product.  Following treatment with pour-on MLs there is often a
suppression of egg laying by Ostertagia.  In response to questions at a
farmers meeting some years ago, Barry McPherson (Merial NZ) said to allow
12 days after treatment with IVM for Ostertagia eggs to start reappearing
in the faeces.  Fort Dodge have an example of it taking up to 15 days after
treatment with moxi pour-on.  We try to drench check 13-14 days after
treatment with a pour-on.

So, a test 7-10 days post-treatment is fine for cattle drenches other than pour-on MLs, in which case you should opt for 14 days.

The test is still imperfect and  results suggesting the possibility of resistance should be followed up, with the assistance of your adviser and the manufacturer of the drench you used.

SL

From: Stephen Love/DII/NSW
To: QAAH-L@DPI.NSW.GOV.AU
Date: 24/05/2010 04:00 PM
Subject: cattle drenches, resistance and rotation – a conversation   //    EMAI turns 20  //   Dunning-Kruger: ‘The Triumph of Stupidity’


Cattle drenches, resistance and rotation – a conversation

WormMail 201005241600    WormMail mailing list (recip. undisclosed);  cc LOs, QAAH-L   (‘Apologies if you get this twice, due to list overlap)

The following is a recent conversation with a northern NSW vet whom we will call ‘Alphonse’.

Hi Steve,

I’ve had a producer enquire about rotating cattle drenches as they have used [ a macrocyclic lactone  pour-on ] for a while and were keen to swap to something else.

I explained that resistance is low in cattle worms and that there isn’t a lot on the market that isn’t an ML but has efficacy against Ostertagia.

Do producers in the New England region have a rotational system with drenches? I suppose a lot of them deal with fluke which complicates matters a bit.

  Cheers,

"Alphonse”
========================

Hi Alphonse

I don’t think we should assume resistance is low in cattle worms in Australia anymore, even if we have somewhat less resistance than in NZ, which is likely.   Here is a table I prepared for Turning the Worm (Issue 22, Dec 2007) ) based on papers in the NZ Vet Journal of Dec 2006:

Gareth Hutchinson has given an excellent overview of cattle worm resistance world-wide (Turning the Worm Issues 11 (May 2003) and 12 (December 2003) ) but that is a little dated given developments in NZ (summarised in TTW Issue 22)  and more recently in Australia (field reports of resistance; plus paper by Lyndal-Murphy et al (2010)).

Apart from a couple of published reports by Eagleson and others[1] relating to BZ resistant T.axei (stomach hair worm) in cattle in Australia, and a recent one by Maxine Lyndal-Murphy and others (2010)[2], there has been a dearth of published reports on cattle worm resistance in this country. However the NZ situation with respect to cattle worm resistance has been a wake up call for us (yes, sometimes we can learn things from Kiwis) and in recent years there have been a number of field reports suggesting we have resistance, including ML resistance, in cattle worms in Australia. The question is, how much?

I think Australian cattle producers should start thinking about doing some post-drench testing from time to time, say a worm egg count 7-10 days after treatment. This is not a perfect test, especially in older cattle, but it is at least a start.  By the way, the post-drench worm test should be no longer than 12 days after treatment in cattle as some cattle Cooperia theoretically can have a prepatent period as short as 12 days.

Most people routinely use MLs, especially pour on MLs. And why wouldn’t they? This applies to the New England as well.

It would be better if people didn’t use MLs all the time….   or if they used combinations, e.g. there is an ML+LEV combi drench in NZ (‘Eclipse’) but I don’t think we have one here yet…

BZs and LEV cattle drenches are quite good against Ostertagia except for inhibited stages. LEV has no effect on inhibited Ostertagia and third generation BZs (albendazole, oxfendazole etc) are roughly 80% effective.  Also BZs and LEV cattle drenches don’t have the persistency that MLs have. But persistency can be a two-edged sword.

So, people could use LEV or BZ drenches from time to time if inhibited Ostertagia were not likely to be an issue (e.g. cattle around 18 months old approaching their second/summer autumn – which is when Type 2 ostertagiasis happens in some areas), and if they had some good grazing management to reduce rate of reinfection with Ostertagia (given the lack of persistency of BZs and LEV compared to MLs).

[1] Eagleson JS and Bowie JY (1986). Oxfendazole resistance in Trichostrongylus axei in cattle in Australia. Veterinary Record 119, 604.

Eagleson JS Bowie JY and Dawkins HJS (1992). Benzimidazole resistance in Trichostrongylus axei in Australia. Veterinary Record 131, 317-318.

[2] Lyndal-Murphy and others (2010. Reduced efficacy of macrocyclic lactone treatments in controlling gastrointestinal nematode infections of weaner dairy calves in subtropical eastern Australia. Veterinary Parasitology 168 (2010) 146–150

SL
Veterinarian, state coordinator-internal parasites
Building C02 Northern Ring Rd [Box U86], UNE Armidale, NSW 2351
      

        

…[snip]…

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cattle drenches, resistance and rotation – a conversation // EMAI turns 20 // Dunning-Kruger: ‘The Triumph of Stupidity’

Cattle drenches, resistance and rotation – a conversation

WormMail 201005241600    WormMail mailing list (recip. undisclosed);  cc LOs, QAAH-L   (‘Apologies if you get this twice, due to list overlap)

The following is a recent conversation with a northern NSW vet whom we will call ‘Alphonse’.

Hi Steve,

I’ve had a producer enquire about rotating cattle drenches as they have used [ a macrocyclic lactone  pour-on ] for a while and were keen to swap to something else.

I explained that resistance is low in cattle worms and that there isn’t a lot on the market that isn’t an ML but has efficacy against Ostertagia.

Do producers in the New England region have a rotational system with drenches? I suppose a lot of them deal with fluke which complicates matters a bit.

  Cheers,

"Alphonse”
========================

Hi Alphonse

I don’t think we should assume resistance is low in cattle worms in Australia anymore, even if we have somewhat less resistance than in NZ, which is likely.   Here is a table I prepared for Turning the Worm (Issue 22, Dec 2007) ) based on papers in the NZ Vet Journal of Dec 2006:

Gareth Hutchinson has given an excellent overview of cattle worm resistance world-wide (Turning the Worm Issues 11 (May 2003) and 12 (December 2003) ) but that is a little dated given developments in NZ (summarised in TTW Issue 22)  and more recently in Australia (field reports of resistance; plus paper by Lyndal-Murphy et al (2010)).

Apart from a couple of published reports by Eagleson and others[1] relating to BZ resistant T.axei (stomach hair worm) in cattle in Australia, and a recent one by Maxine Lyndal-Murphy and others (2010)[2], there has been a dearth of published reports on cattle worm resistance in this country. However the NZ situation with respect to cattle worm resistance has been a wake up call for us (yes, sometimes we can learn things from Kiwis) and in recent years there have been a number of field reports suggesting we have resistance, including ML resistance, in cattle worms in Australia. The question is, how much?

I think Australian cattle producers should start thinking about doing some post-drench testing from time to time, say a worm egg count 7-10 days after treatment. This is not a perfect test, especially in older cattle, but it is at least a start.  By the way, the post-drench worm test should be no longer than 12 days after treatment in cattle as some cattle Cooperia theoretically can have a prepatent period as short as 12 days.

Most people routinely use MLs, especially pour on MLs. And why wouldn’t they? This applies to the New England as well.

It would be better if people didn’t use MLs all the time….   or if they used combinations, e.g. there is an ML+LEV combi drench in NZ (‘Eclipse’) but I don’t think we have one here yet…

BZs and LEV cattle drenches are quite good against Ostertagia except for inhibited stages. LEV has no effect on inhibited Ostertagia and third generation BZs (albendazole, oxfendazole etc) are roughly 80% effective.  Also BZs and LEV cattle drenches don’t have the persistency that MLs have. But persistency can be a two-edged sword.

So, people could use LEV or BZ drenches from time to time if inhibited Ostertagia were not likely to be an issue (e.g. cattle around 18 months old approaching their second/summer autumn – which is when Type 2 ostertagiasis happens in some areas), and if they had some good grazing management to reduce rate of reinfection with Ostertagia (given the lack of persistency of BZs and LEV compared to MLs).

This is a good question [snip]…maybe I should make it into a ‘Dear Alphonse’ for WormMail?  

[1] Eagleson JS and Bowie JY (1986). Oxfendazole resistance in Trichostrongylus axei in cattle in Australia. Veterinary Record 119, 604.

Eagleson JS Bowie JY and Dawkins HJS (1992). Benzimidazole resistance in Trichostrongylus axei in Australia. Veterinary Record 131, 317-318.

[2] Lyndal-Murphy and others (2010. Reduced efficacy of macrocyclic lactone treatments in controlling gastrointestinal nematode infections of weaner dairy calves in subtropical eastern Australia. Veterinary Parasitology 168 (2010) 146–150

Stephen Love
Veterinarian, state coordinator-internal parasites
Building C02 Northern Ring Rd [Box U86], UNE Armidale, NSW 2351
T: 61 2 6738 8519     

      

        

Extras

A bit of history: EMAI turns 20


Source: NSW DPI Intranet

Stupidity and self-confidence – http://www.abc.net.au/rn/scienceshow/stories/2010/2893602.htm

"The verdict was in; idiots get confident while the smart get modest, an idea that was around long before Dunning and Kruger’s day. Bertrand Russell once said, ‘In the modern world the stupid are cocksure while the intelligent are full of doubt.’ From his essay ‘The Triumph of Stupidity’, published in 1933. "

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Zoonoses ? animal diseases transmissible to humans

Zoonoses – animal diseases transmissible to humans       WormMail 201005171500   (WormMail list; recip. undisclosed)

I&I NSW has published Primefact 814, ‘Zoonoses – animal diseases transmissible to humans’

Available at:

http://www.dpi.nsw.gov.au/agriculture/livestock/health/humans/zoonoses

and attached:

Regards

SL

Veterinarian / State Worm Control Coordinator
Industry and Investment NSW ~ Primary Industries
Armidale District Office ~ Tel: 61 2 67388519

  I&L NSW-PRIMARY INDUSTRIES
* LIVESTOCK HEALTH INCL WORMS pages  http://www.dpi.nsw.gov.au/agriculture/livestock/health
* OFFICE DIRECTORY  http://www.dpi.nsw.gov.au/aboutus/about/office

OTHER
* WORMBOSS  http://www.wool.com/wormboss
* WORMMAIL on the WEB  Now at   https://wormmailinthecloud.wordpress.com/  or    http://wormmailinthecloud.posterous.com/  (moved 25/3/10)  from  http://auswormmail.wordpress.com)
* SHEEP CONNECT NSW  http://www.sheepconnectnsw.com.au

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WormMail: Sheep Connect NSW – Keeping you in The Know

Sheep Connect NSW – Keeping you in The Know        

WormMail 201005171230  (WormMail mailing list (and others)-recipients undisclosed)

Here is a new resource, being developed by I&I NSW and AWI.   You may be familiar with the term ‘Sheep Connect’ from projects of the same name in other states, although the flavour/approach varies.

To keep in the know, make sure you go to Sheep Connect NSW and register.  This service can only get better as it gathers momentum and website development continues.

It already contains some parasite-related events, so it is obviously shaping up as a top class resource.  ๐Ÿ™‚

Soon you will be able to register upcoming events through the website and get updates on upcoming events of interest to you.

For the time being however, if you want to register events, get a registration form from your local Livestock Officer, Sheep and Wool, or send an email to sheep.connect@industry.nsw.gov.au  for further information.

There is a Sheep Connect NSW Industry Update scheduled for Armidale on 8 September 2010.

See full media release below.

Sheep Connect NSW
Industry & Investment NSW, Forest Rd, Orange NSW 2800
T:   02 6391 3901
E:  sheep.connect@industry.nsw.gov.au
W: www.sheepconnectnsw.com.au

So, now you have TWO ‘must have’ registrations  ๐Ÿ™‚   :

WormBoss News

Sheep Connect NSW

(and WormMail of course  ๐Ÿ™‚

Regards

SL

Veterinarian / State Worm Control Coordinator
Industry and Investment NSW ~ Primary Industries
Armidale District Office

  I&L NSW-PRIMARY INDUSTRIES
* LIVESTOCK HEALTH INCL WORMS pages  http://www.dpi.nsw.gov.au/agriculture/livestock/health
* OFFICE DIRECTORY  http://www.dpi.nsw.gov.au/aboutus/about/office

OTHER
* WORMBOSS  http://www.wool.com/wormboss
* WORMMAIL on the WEB  Now at   https://wormmailinthecloud.wordpress.com/  or    http://wormmailinthecloud.posterous.com/  (moved 25/3/10)  from  http://auswormmail.wordpress.com)
* SHEEP CONNECT NSW  http://www.sheepconnectnsw.com.au

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Wormmail: lectin staining assay to identify Haemonchus eggs – an update

WormMail 201005131530

 Dr Dieter Palmer has just sent me this note (published here with permission):

"With the financial support of the sheep CRC I have done further work on the lectin staining assay to identify Haemonchus eggs.

The assay is now fairly simple, takes about 3 hours with  hands on time of only 15-20 minutes per sample.

The cost for the consumable is less than A$ 5.00 per samples and the only requirement for laboratories wishing to use this test is the availability of a fluorescent microscope and a small centrifuge.

The sheep CRC have provided me with funds to demonstrate the technique to other laboratories in Australia. I am planning to offer the demonstration to (various interested) laboratories."

The lectin assay was discussed in  WormMail 2010.02.11 (archived at https://wormmailinthecloud.wordpress.com/2010/02/11/lectin-staining-to-identify-haemonchus-eggs/ )

For further information, contact  Dieter Palmer. His contact details follow:

Dieter Palmer, BSc (Hons), BVSc, PhD
Senior Veterinary Immunologist/Parasitologist
Animal Health Laboratories
Department of Agriculture and Food WA
3 Baron Hay Court
SOUTH PERTH WA 6151

Locked Bag 4
BENTLEY DELIVERY CENTRE  WA 6983

Tel: 08 9368 3674
Fax: 08 9368 3427
Email: dpalmer@agric.wa.gov.au  

Regards

SL

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WormMail: a conversation regarding the importance of Nematodirus in sheep

WormMail 201005131100

Following is the start of a conversation regarding Nematodirus (thin-necked intestinal worm; ‘Nem’) with Graham Lean following on Paul Nilon article on Parasites in Sheep in Tasmania( Turning the Worm newsletter Issue 26, May 2010; also here).

Graham has given permission to put this in a WormMail i.e. essentially public).  If you would like to comment – and agree to have you comments added to a final compilation to be published in WormMail i.e. public)- then feel free to reply to this email.

Here is the conversation:

 
[GL]: Hi Steve,

[GL]: I enjoyed Paul’s article.  I thought it was very good.  

[SL]: I agree. Interesting stuff and nice writing style.   It was the second in a series…the first (some time go) being one on sheep worms in the Falklands….
(Derek Clelland, TTW Issue 5, July 1999)

[GL]: I also thought that his observation of Nematodirus was similar to mine in SW WA when I was there and also here in western Victoria.  Some parasitologists agree with our view, others dismiss it.

[SL}: Here is what Paul Nilon said in his TTW article

Nematodirus spp [3]  (don’t ask which species) predominates in dry summers and autumns.  While it is regarded as relatively benign in other parts, in Tasmania it can cause significant parasitism, particularly in weaners.  Moreover, because of sporadic egg output FEC  Faecal worm egg count. triggers for treatment are low (150 epg).


[SL]: My view….   It is a second order parasite ( in NSW at least) compared to Haemonchus-Ostertagia-Trichostrongylus in sheep –  but under certain circumstances can be important…


[SL]: eg.


* young sheep – more vulnerable.

* certain seasonal conditions … eg rain after prolonged dry spell…through which the tough Nem eggs can survive for extended periods

* certain management conditions…e.g paddocks set-stocked with young sheep or regularly used by young sheep…resulting in higher numbers of Nem eggs

* other stressors contributing….  nutrition, weather, other parasites

* drench resistance


[SL]: And…   there may be clinical disease before Nem egg counts rise much at all…due to large numbers of immatures

[GL]: Agree with all that.  Nicely put.


[SL]: Nem  (N filicollis at least?) is a big deal in NZ…but it was not always so.   I seem to recall it become a 1st order parasite only since the 1960s? (Love and Hutchinson 2003) ….  not sure why….Changes in farming practices??
(Our NZ colleagues may help out here)

[SL] [Postscript] Regarding Nematodirus species  in sheep in NZ, Pomroy lists N. filicollis of major importance, and various other species (spathiger, helvetianus, and abnormalis) of minor importance.(Interestingly Pomroy also lists Trichonstronglyus axei – stomach hair worm- as of major importance, which is generally not the case in Australia).

[SL]: Maybe we can run Paul’s comments (in the Tassie article), your comments, and my comments above….  through WormMail…and invite comments…   then compile all the comments into a  follow-up??

[GL]: More than happy to see that occur.

 [GL]: Hate to open up a can of worms (yes, I couldn’t resist the pun), but this might be worth looking in more detail at some stage in turning the worm, or worm mail?  What do you think?

Cheers,   GL

[GL]: =  Graham R. Lean BVSc, MAAAC, authorised rep AFS License No. 316516 (futures) PO Box 105 Hamilton VIC 3300 Australia Principal Consultant Graham Lean and Associates Farm Business Advisers

[SL]: = Stephen Love

References

Pomroy WE (1997).Internal helminth parasites of ruminants in New Zealand. In, Sustainable control of internal parasites in ruminants, Animal Industries Workshop, June 1997, Lincoln University, NZ. Ed: GK Barrell

Nematodirus at WormBoss:  http://www.wool.com/Grow_WormBoss_Know-your-worms_Thin-necked-intestinal-worm.htm

Love and Hutchinson (2003):

"Nematodirus spathiger is a very common parasite of young Australian sheep, and usually relatively
non-pathogenic unlike the situation in New Zealand where this parasite inexplicably become more
important from the 1960s. Heavy infections, scouring and ill thrift with mortalities can be seen in
young sheep under or soon after drought conditions in Australia (south western NSW, for example)
presumably become Nematodirus eggs are relatively desiccation–tolerant. Clinical nematodirosis is
also not uncommon in young lambs in irrigation areas such as the Riverina area of southern New
South Wales."   (Love and Hutchinson 2003)  or Love SCJ, Hutchinson GW (2003). Pathology and diagnosis of internal parasites in
ruminants. In Gross Pathology of Ruminants, Proceedings 350, Post Graduate Foundation in Veterinary Science,
University of Sydney, Sydney;Chapter 16:309-338.

For more information on service providers such as Paul Nilon and Graham Lean  go to: http://www.wool.com/Grow_WormBoss_Professional-service-providers.htm

Regards

SL

Veterinarian / State Worm Control Coordinator
Industry and Investment NSW ~ Primary Industries
Armidale District Office ~ Tel: 61 2 67388519

  I&I NSW-Primary Industries

~ LIVESTOCK HEALTH INCL WORMS pages  http://www.dpi.nsw.gov.au/agriculture/livestock/health

~ OFFICE DIRECTORY  http://www.dpi.nsw.gov.au/aboutus/about/office

WORMBOSS  http://www.wool.com/wormboss

WORMMAIL on the WEB  Now at   https://wormmailinthecloud.wordpress.com/  or    http://wormmailinthecloud.posterous.com/  (moved 25/3/10)  from  http://auswormmail.wordpress.com)

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Turning the Worm # 26 May 2010 now on-line

WormMail 201005111630

Issue 26 of the Turning the Worm Newsletter is now on-line.

http://www.dpi.nsw.gov.au/aboutus/resources/periodicals/newsletters/turning-the-worm/

Some of the content has appeared in WormMails / is mirrored at ‘wormmailinthecloud’ (see below for URL)

Contents of this issue:

Regards

SL

Veterinarian / State Worm Control Coordinator
Industry and Investment NSW ~ Primary Industries
Armidale District Office ~ Tel: 61 2 67388519

  I&I NSW-Primary Industries

~ LIVESTOCK HEALTH INCL WORMS pages  http://www.dpi.nsw.gov.au/agriculture/livestock/health

~ OFFICE DIRECTORY  http://www.dpi.nsw.gov.au/aboutus/about/office

WORMBOSS  http://www.wool.com/wormboss

WORMMAIL on the WEB  Now at   https://wormmailinthecloud.wordpress.com/  or    http://wormmailinthecloud.posterous.com/  (moved 25/3/10)  from  http://auswormmail.wordpress.com)

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