WRML. New England Grazier Updates. DPI media release on barber’s pole worm

TO: WormMail list (recip. undisclosed).  WRML.20110629.New England Grazier Updates.DPI media release on barber’s pole worm


See attached PDF.

More information:

Livestock Officer – Sheep & Wool, NSW Department of Primary Industries, Armidale
telephone: 02 67 388 505  mobile: 0428 968 159  email: jim.meckiff@industry.nsw.gov.au





The trouble with science is that its done by people.    (Further to Karl Popper on Black Swans)

27052011NEGU flyer.pdf Download this file


WRML: [1] Frosts don’t finish Haemonchus [2] Naphthalophos resistance (chatting with Alphonse) [3] article in The Land on quarantine drenching

TO: WormMail list (recip. undisclosed).  

WRML.20110628.1 Frosts don’t finish Haemonchus 2 Naphthalophos resistance 3 article in The Land – quarantine drenching

Frosts don’t finish Haemonchus

(I wrote this little piece for elsewhere, mainly because I get the impression that some think winter spells the end for problems with Haemonchus)

It is well known that the eggs of barber’s pole worm of sheep (Haemonchus contortus) are particularly sensitive to cold and desiccation. It is wrong to conclude from this, however, that this worm will not be a problem over winter. Here’s why.

The top three worms of sheep in Australia are barber’s pole worm (Haemonchus), black scour worm (Trichostrongylus) and small brown stomach worm (Teladorsagia(Ostertagia)). These have differing preferences when it comes to climate and weather. This is largely due to differences between the eggs of these three worm types.

Although the eggs of these worms look similar – almost identical – under the microscope – they have different needs. Haemonchus eggs are most sensitive to cold and desiccation: they need it to be more than 10 degrees by night and 18 degrees by day. And compared to the other important roundworms, they need lots of moisture.  This explains why Haemonchus is mainly a warm weather parasite and is particularly a problem in summer rainfall areas – or other areas experiencing unseasonably wet summers.

Barber’s pole worm’s other Achilles Heel is that the eggs are short-lived, being viable for just 5 days or so once deposited in dung on pasture. It’s strength however is its fecundity: barbers pole worm produce a lot more eggs -around 10,000 per day- than most other important worms except for liver fluke.

But the third stage or infective larvae of these top three worms are a different story. While barbers pole worm is the weakling in terms of its eggs, it keeps up with the others when it comes to survivability of infective larvae on pasture.

So, the barber’s pole worm life cycle stops in winter, because its too cold for the eggs, assuming it’s consistently below 10 degrees overnight.

But the larvae live on. Sure, their numbers won’t be topped up with new hatchings over winter, but all those larvae produced on pasture in late summer and autumn won’t die in a hurry. In fact the larvae live longer if it is cool to cold  – about twice as long – compared to when it is warm to hot.

Come early Spring, there will still be some infective larvae on pasture surviving from autumn. As an aside, the liver fluke situation is similar to that for barber’s pole worm: it’s infective stages on pasture (metacercariae) will survive over winter, albeit in dwindling numbers, especially if moisture is available.

So, if conditions on your farm were good for barbers pole worm in the several months leading up to winter, don’t rest on your laurels and think that frosts have fixed the problem. Your sheep could still be picking up barber’s pole worm – not to mention scour worms – over winter.

Not surprisingly the last ‘word’ is: Don’t guess, WormTest.

SL  27/6/11

Naphthalophos resistance

   (‘Eaves-dropping on a conversation I had with a veterinary colleague. Let’s call him ‘Alphonse’).

"Alphonse, ‘sorry for the lateness in replying: bulging INBOX syndrome.

Naphthalophos(NAP; ‘Rametin’, Combat’ etc) intrinsically is not highly effective ( ie not >95% effective) against Trichostrongylus sp, Teladorsagia (Ostertagia), or immature (L4) Haemonchus (Hc).   Typically it is only 70-90% effective.  (I don’t have a peer-reviewed source for the statement re L4 Hc, but it seems to be accepted).

( Neil Cooper and others (1996, Naphthalophos combinations with benzimidazoles or levamisole as effective anthelmintics for sheep. Aust. Vet. J. 74, 221–224) showed that NAP alone, in a number of worm egg count reduction tests, produced egg count reductions ranging from 58-98% (presumably burdens dominated by Trichostrongylus and/or Teladorsagia). NAP in combination with either a BZ or LEV produced better results)

So, this might explain what appears to be resistance in many if not most worm egg count reduction tests (WECRT, aka FECRT, ‘DrenchTest), eg  WEC reduced by less than 95% 7-14 days post-treatment.

However, there ARE some fair dinkum, reported cases (peer reviewed journals) of resistance to NAP (one for Haemonchus, one for Trichostrongylus). The two I know of are Green et al and Le Jambre et al.  

(I mentioned these two references in a recent WormMail. If I wasn’t so lazy and dying to have some lunch, I would dig them up for you…:-).

Alphonse, there was a suspicion of fair dinkum resistance of Hc to NAP in your backyard, at the famous Wallangra farm, from which came the first Australian reports of Haemonchus resistant to closantel (first detected by Warialda District Veterinarian Phil Kemsley; confirmed, characterised and reported by Rolfe et al (including Kemsley),  and to moxidectin.   But the NAP situation was never clarified.

Then look at some of the results for NAP-combinations in WECRTs by Andrew Biddle…(eg the Glen Innes property with resistance to abamectin+BZ+LEV+CLOS – also mentioned in recent WormMails). The NAP results may just be due to lots of Hc L4s being there at time of treatment, or………….

Very cold here…. Haemonchus is not happy (the eggs at least. ). Pity.

NSW Northern Tablelands.


I dug up the references:

Green PE, Forsyth BA, Rowan KJ and Payne G (1981). The isolation of a field strain of Haemonchus contortus in Queensland showing multiple anthelmintic resistance. Australian Veterinary Journal 57(2): 79–84.

Le Jambre LF, Geoghegan J and Lyndal-Murphy M (2005). Characterization of moxidectin resistant Trichostrongylus colubriformis and Haemonchus contortus. Veterinary Parasitology 128: 83–90.    (" the TcMOX-R strain* should be considered resistant to NAP…" )  * ie moxidectin-resistant T.colubriformis.  ("Both NAP and LEV are effective options for the
control of HcMOX-R." **)  ** ie moxidectin-resistant Haemonchus contortus.   ("The TcMOX-R strain is one of the first, if not the first, MOX resistant strain of this parasite to be described. The existence of this strain proves that Australian T. colubriformis has sufficient genetic variability to develop MOX resistance.").  By way of background: these worms originated from goats in SE Queensland.

Sheep drench resistance and quarantine drenching – Vet Talk-The Land (NSW, Australia) 23 June 2011



Read no further…

Popper and Black Swans

"Popper set the standards by which hypotheses should be structured.  A well-stated hypothesis should be able to be falsified.  That doesn’t mean it will be falsified, but it should be structured in a way that it can be.  And real scientists – of which, sadly, there are all too few in the field of nutrition – don’t try to confirm their hypotheses: they try to refute them.

One of the examples Popper used in explaining how a hypothesis should be established involved swans – white and black. 

He used the following as an example of a good hypothesis:  All swans are white.  He made the case that this hypothesis cannot be confirmed by simply pointing out more and more white swans.  The hypothesis can be strengthened by doing so, but it can’t be proven. 

It can, however, be disproved by the discovery of even a single black swan.  Popper argued that scientists should be working to find black swans instead of simply adding more and more white swan sightings to their data.  The more effort scientists expend to find a black swan without finding one, the more their hypothesis is strengthened.  Diligently searching for black swans is a much more valid scientific endeavor than simply looking for more white swans.

Many scientists don’t want to hunt for black swans, however, because they don’t want to blow up their hypotheses.  The easy way to bolster their hypotheses is to continue to tally up all the white swans they find and forget about looking for black ones". – Michael Eades

WRML: Question from Arthur. CARS. Saffers and Startect-REDUX. DrenchGroup Info on Label-REDUX. Flesh eaters. Solstices

To: WormMail mailing list (recip. undisclosed).

WRML.20110623.Question from Arthur. CARS. Saffers and Startect-REDUX. DrenchGroup Info on Labels-REDUX. Flesh eaters. Solstices

QA (Question from Arthur)

Arthur Le Feuvre, as many would know, is a consultant/freelance operative, was the first WormBoss Team Leader, and formerly a sheep and wool expert employed by Queensland DPI.

He asks this question:

"I would be very interested to know from our learned colleagues (most of whom I am sure are on your WormMail list!) what they believe is the answer to this question:

“What is the percentage of sheep producers (in your country/region) who have any factual information on the efficacy of a drench on their property before they purchase it?”
I’d be pleased to get the opinion on the question from as many countries/regions as possible.  My estimate for Australia is that only 10% to 20% have it.

Replies to Arthur please (my cup as well as my inbox overfloweth):  arthur@vetspets.com.au

Arthur will collate and share what he has found.


From Dr Peter Hunt, CSIRO, Armidale:

" …… we are trying to get more interest in our database of drench resistance information (http://vbc.med.monash.edu.au/cars/cars.py/). The idea is to catalogue all types of investigation from field tests (faecal egg count reduction tests) right through to more complex molecular work in one place.

It should be a more sophisticated way of presenting the "state of play" than that used by the "herbicide crowd", but then we are more sophisticated aren’t we?

There’s also a place where strains available for swapping/sharing can be indicated. Happy for you to advertise the database to any one who is interested.

CARS stands for the "consortium for anthelmintic resistance and susceptibility"  see http://wikisites.mcgill.ca/CARS/index.php/Main_Page

  Its a group of fanatical academics trying to fund research into molecular markers for drench resistance. I seem to remember being on this track almost 20 years ago, and still am trying…One day a simple test from a single faecal sample…

Saffers and Startect – REDUX (see recent WormMail)

Some notes:

– Comments were not so much about  “Companies”… but  “some companies”

– Some but not all of SA’s  leading parasitologists oppose the use of combinations

  – SAVA = South African Veterinary Association

  – DM’s last name is Midgley, not Midgely..   (mea culpa: I must have been thinking of annoying insects….which I am sure DM is not ! πŸ™‚

Drench Group Info on Labels -REDUX  (see recent WormMail)

* Comment from  Steven Maeder,  Director Clinical Development, VMRD Pfizer Animal Health

  "A similar system has been in place in South Africa for many years and also in the UK I believe.  

An important new driver for this initiative in my view is the recent decision by WHO to name all new anthelmintics for animals with the suffix ~ antel despite their mechanism of action e.g. derquantel and monepantel.  It is now impossible for farmers (and vets?) to determine if anthelmintics have a different mechanism of action by looking at the generic name.  This was possible in many cases in the past.

Another initiative that always made sense to me was that it was compulsory in RSA to include the active ingredient of a drench in any advertisement to aid in drench selection and prevent rotation/alternation between brand names being considered as rotation/ alternation between drench classes.  

  I thought I would point this out first as Jan van Wyk will likely once again be highlighting the dominance of RSA over the backward “antipodes” as he did with tapeworms recently!  

– SM."

VMRD = Veterinary Medicine Research and Development   RSA= Republic of South Africa

* Comment: I really like the idea of a standardised colour code for the various drench groups.  (A.LF)

( I think Gareth Kelly (UNE) had the colour idea. Back in 2000, I was only thinking in black and white -SL)

(Yes, we now have four different ‘-antels’ on the market that I can think of: closantel, praziquantel, monepantel, derquantel (not yet in AU), all of them in different groups – SL).

* Comment:  Dr Peter Hunt, CSIRO, Armidale:

"I notice the herbicide groups are simple letters, rather than our usual more complex letter combinations, perhaps we should go that way too.  I guess you would have to produce an AgFact to explain that A=BZ=benzimidazoles=white drenches etc too, but I guess you have already thought of that."

Reply (SL): I thought about simple letters, like the herbicide crowd?, based on chronology….   eg A = BZs, B= LEVs, C=MLs…..etc….    (tho some narrow spectrums…eg salicylanilides hit the ground before MLs….)….but then opted for letters/abbrevs. the meaning of which were more or less self-evident….

* Another comment

"What are we coming to when people that run multi million dollar businesses need this type of spoon feeding. Its ******** and farmers should educate themselves!!!! "

(Fair point – SL).

* Comment – MR @ Forbes

"Hi Steve

My two bobs worth….. on group info on labels..

I think the idea of the drench groups is paramount – as you point out its on all herbicide labels, and I think it could even stretch to other products eg lousicides, insecticides, etc, as we all know resistance occurs in all groups.

The colours may be a problem given the graphic designer requirements and all the artwork stuff, but I do know on the herbicide labels its just in black and white – thereby limiting the amount of trouble for the designers…. maybe plain packaging for all products in olive green might be the go?? πŸ™‚ *

I often use the argument (as I did in my current column) that you wouldn’t buy a drum of herbicide without consulting an agronomist, so why do similar with animal health products…… changing this mindset might increase the amount of product choice available to consumers when they go to buy a drum of drench…. all of the herbicides are stocked by all the shops, so why not drenches……..??????

Go for it – maybe its something that could gain extra traction if NSW Farmers could lobby for – its simple, generic,…

*(Reference to proposed changes to cigarette packaging. πŸ˜‰   I can imagine olive green drench drums with health warnings (about using ineffective drenches) in the form of pictures of diseased sheep. – SL)

Mystery of the Flesh Eaters

Transcript:  http://www.abc.net.au/catalyst/stories/3245837.htm

Vodcast: http://www.abc.net.au/catalyst/vodcast/default.htm

"Known as an insect pathogen, Photorhabdus normally lives inside a small worm. The worm attacks by penetrating the skin, or cuticle, of the insect. Once inside, the worm vomits up the Photorhabdus bacterium. Toxins released by the bacterium kill the insect and preserve its body. The worm them multiplies, and uses the insect cadaver for food.

Attacking a human is vastly different to attacking an insect. So it seemed that perhaps this bacterium was carried by a different vector. "

Southern hemisphere solstices and equinoxes, 2011 (as per Aust Weather Calendar)

Season Day Date Time

Autumn equinox Monday 21 March 2011 10.21am EDT
Winter solstice Wednesday 22 June 2011 03.16am EST
Spring equinox Friday 23 September 2011 07.04pm EST
Summer solstice Thursday 22 December 2011 04.30pm EDT

EDT: (Australian) Eastern Daylight Saving Time
EST: (Australian) Eastern Standard Time
Data obtained from Geoscience Australia.


Antipodes: ant-centipede hybrid


WRML: Saffers, Startect, combos, quarantine drenches etc

TO: WormMail mailing list (recip. undisclosed)     WRML.20110622. Saffers.Startect. combos. quarantine drenches.etc

Saffers and Startect

Most of you know that after a 20-25 or so year hiatus, we recently got two new drench groups:

        * the AADs, represented by monepantel, ("Zolvix", Novartis), and

        * the spiroindoles, represented by derquantel (combined with abamectin, in "Startect" (Pfizer).

The ‘world’ launches for these two were in New Zealand, monepantel in autumn 2009, and derquantel in July 2010.

Australia got monepantel in Spring 2010. We have yet to get derquantel (Perhaps the end of 2011 or early 2012?)

I just heard from a South African contact that Startect has hit the ground in South Africa.

Dr Dave Midgely was with Pfizer SA for the last 6 years, but  resigned to pursue a career as a Veterinary Consultant.
He  was in private practice in the Southern Cape area (near Caledon/Ian Herbst) for 20 years prior to that.

I had a ‘conversation’ with Dr Midgely: I think it is good to talk to those outside your own backyard (NSW in my case): ‘Iron sharpens iron’ and all that.

Dave told me:

"I spent some time with Faffa Malan recently launching STARTECT in South Africa (SA) and he recommended that I contact you
I have a keen interest in parasitology and am involved in the fight against resistance on ground level… "

"Startect (derquantel+abamectin, Pfizer) was launched to vets at our LHPG Congress (Livestock Health and Production Group) in March and to Farmers and Co-ops towards the end of May and in June.

"I spent 3 weeks with the launch team talking about positioning it…

"We have different “schools of thought” regarding the use of combinations in SA – the “old school” still fighting strongly against it!

"I am on the other extreme regarding combinations as a “must” – that is why I enjoy your newsletters that Faffa has passed on so much!

"The resistance issue is a reality – farmers seeing and feeling it in their pockets. "

Dave went on to say:

"It might be worth mentioning that Faffa Malan and myself tried to convey a few “basic messages” to vets, farmers and Co-op personnel:

       * The first was to know your “status” – i.e. resistance status of the worms on your farm

        *Next we felt that it is important to know the status of the farm from which you are buying in sheep, as this might influence quarantine decisions.

"If you are one of a “lucky” 7 % of farmers on whose farm no resistance was found in a recent survey undertaken by Pfizer (Van Schalkwyk and Cox), on whose farms all 5 tested anthelmintic groups were still > 95% effective, you would do anything to prevent resistance worms from entering your property!

"On the other hand, I (as a consultant/vet) would have a totally different approach if I I/my client was one of the 17% “Haemonchus” farmers on who’s farms there was resistance to all 5 the tested groups…

"In which case I might WANT susceptible parasites that I buy in and would like to use them to “dilute” my resistant population!

"Hence the importance of QUARANTINE treatment and of knowing the STATUS of both farms!

"I believe that this opens up major opportunities for private practitioners in SA (and elsewhere) to get involved in parasite control again.

"Next up was explaining REFUGIA and it’s application in parasite control – especially “managing refugia” through dose and leave or move and dose, instead of the “old” dose and move recommendation.

" I was/am still shocked by farmer’s responses – some of them said that it was the first time that they “heard” this message, despite it being propagated already for many years. It seems that the message has not/is not reaching ground level and that we will have to do a lot more to get it across!

" We further tried to bring across the message that parasite control has become more “complex” and that farmers should THINK before just dosing/drenching.

Harry Truman (?) apparently said – “If you can’t convince them, at least confuse them…”. One farmer said that he was confused before attending one of the meetings and was still confused afterwards, but just on a higher level!

I interrogated Dave further:

SL:  "all 5 anthelmintic groups?….which are they? "

DM:  "Avermectin, BZ, LV, Closantel plus organophosphates. These are the five “major” groups registered in SA.

"No combinations were used in this survey – ‘tried to compare results of those done by/used by Jan van Wyk in the 1980s.

"At that stage moxidectin was still distributed by Bayer – before Pfizer took over Fort Dodge and it was unfortunately not included!


SL:  " ‘individualised risk analysis for quarantine treat.: nice in theory, but how many accurately know their own anthelmintic resistance (AR) status as well as the farm from which they are sourcing sheep??

DM: "I have started by doing a resistance test (drench test/FECRT) with every drenching.

"Flip van Schalkwyk started with “vacuum-sealing” of samples – which can then be kept at room temp for long periods. In this way farmers take initial sample, wait 10-14 days for second sample and then send them to lab together.

"What I like about this is that farmers can also start seeing that all generic equivalents are not the same…

"After 2-3 different groups being used (normally after the second group shows resistance) we have a reasonably clear picture of what is going on.

"I found that with this approach I can convince more farmers to then do a more advanced FECRT including COMBO’s which has been “shot down” by our leading parasitologists in SA for many years (and are still being done so at present!).

"We had a good Livestock Health and Production group congress in March where we also had a “wet lab” for attendees (private practitioners).
Unfortunately all these things are part of a process – but it is better to start somewhere, than not at all!

SL: "diluting AR resistant worms with imported worms/sheep:   this has been discussed here as well (in AUS), but…see above (not accurately knowing AR status), and also… I wonder how the numbers stack up…. importing say 10,000 anthelmintic susceptible (AS) worms, vs a billion AR worms (plucking numbers out of the air) already on farm.   The imported worms would need some sort of ‘fitness’ advantage to gain ascendancy….and/or you import them when there are very few ‘home grown’/resistant) worms on pasture….eg   the dead of summer in a Mediterranean climate (eg southern Western Aus, parts of South AUS), with lots of cereal stubbles.

DM: "Once again, yes this is still very “theoretical” but a start in the right direction.

"I believe that our vets should become more involved in practical parasitology – anthelmintics are sold predominantly by Co-ops here and vets in private practice (PP) actually make very little money out of “parasitology”.

"I was in PP for just over 20 years and wonder if it made up 1% of my turnover! Why then spend time on something that gives so little “return”?

"By doing faecal samples I found that I got much closer to where the action is.

"In my opinion the fight against resistance is useless if we cannot get the PP involved! So the recommendation is – start somewhere.

(“Begin with the end in mind” – Stephan Covey). Knowing what the situation is, is the “cherry on the cake”. Next best is just “cleaning up” all “in-comers”… This does depend on where you farm. We have some areas where the situation is fast becoming “desperate”. With present wool and mutton prices being the highest ever, farmers are still “coining” it despite problems like “resistance”.  

SL: "By the way, I believe there have been attempts to re-populate sheep farms in AUS with AS worms, at great expense but with little success. (RB Besier could enlighten us on this).

DM: "How long does it take for resistance to be “seen”? Would it not take as long to see a change in direction? I once again see this as a process. And a very slow one indeed, but once again – a better option than just “ignoring” it!

SL: "the ‘drench and move’ dogma of old: yes, farmers don’t always appreciate you telling them it’s a two-edged sword: great for worm control (slow reinfection) but bad for resistance management (few worms in refugia), with the strength of these effects depending on just how clean the paddock is – and people mean different things by ‘clean’.   eg those in winter rainfall areas, especially the Mediterranean climate variant, regard  their cereal stubbles in summer as ‘clean’, whereas a grazing only property (no cropping) in the summer rainfall zone of NE NSW or SE Queensland might regard a pasture that has been sheep-free for 3-4 months over summer as relatively ‘clean’ – but the two examples are poles apart.

DM: "The message has not come across yet. “Sheep Politics” can be blamed – conflict of interest – companies chasing budgets vs researchers who do excellent work but do/did not take “farm economics” into account properly! It all comes down to the understanding and “selling” of the REFUGIA principle.

SL: "Complexity? Yes, likewise here (in AUS). Worm control messages are ‘too complex’.   Maybe we have to major on the main drivers, and leave the detail on lesser issues to those who are really interested and have already made the main things the main thing (to parrot Stephen Covey).

DM: "Have read his books, but missed this one in the past – I like it!

"Once again – it all depends on how serious the farmer is about worm control.

"I am getting more and more farmers who are being “hit” by parasites – I find that it doesn’t help crying wolf.

"But when I/we do get a foot in the door, the ball is in our hands. While Faffa and I were “on the road” we propagated a more “integrated approach”; another colleague presented/propagated a “dosing program” at a mini congress of a regional branch of the SAVA????? (I found that the parasites did not read the same text books and e-mails that we do!)

SL:  "The other day, I was thinking: "Consultants are a type of parasite, but like some parasites can provide long term benefits to the host"

Some consultants might take offence…….    πŸ™‚    But, I could then go on to liken public servants  ..  <cough>….public sector employees  … to parasites as well…   πŸ™‚ "


 (This good humoured reply from DM followed, no doubt buoyed by expectations that SAf would wallop the Wallabies at Rugby….)

"I do believe that what you say of consultants is true. Will “quote” you in future on this one!

"I was told last week that consultants are like wethers  – knowing exactly what to do, but can’t do it themselves!

(All the above quoted with permission: DM must be fearless; perhaps he played for the Springboks)


As an aside, we talk a lot about resistance, but we have to remind ourselves what our ultimate objectives are (and if they align with farmers’ objectives!)

As venerable Scotsman GD Gray reminded me some years ago, resistance is only an issue to the extent that it affects our ability to manage worms. We have to remember that worms are the issue.



Hard on the heels of Apple talking up ‘the cloud’ – specifically iCloud – here is a piece regarding management and the cloud. Click HERE.

WRML: Leathwick on resistance;- sequential drenching? drench group info on labels? complicated tapeworm nomenclature; lessons from C.difficle? Bot

To: WormMail list (recip. undisclosed).  WRML.20110621 (winter solstice downunder)

Dr Leathwick on resistance    http://issuu.com/ruralnewsgroup/docs/rn-june-7-2011    page 61

Here is a piece in Rural News NZ (7 June, 2011) by NZ scientist DM Leathwick that might be of interest:


The NZ colleague who brought this to my attention said that, unfortunately, farmers might be more interested in the other article on the same page (‘Birds of a Feather’, a photoshoot of some Massey University vet students who had produced a fund rasing calendar).

‘Sequential’ drenching at the quarantine drench

A reader pointed out that ‘sequential’ drenching in a recent piece on ‘quarantine drenching UK style’ might be misunderstood.

What was meant was ‘concurrent’ drenching: ie up the race with one drench then up the race with another drench.

Put Drench Group information on Product Labels?? …time to revisit this??

About 10 years ago, inspired by a poster by the herbicide crowd – who put herbicide group information onto product labels – I wrote to sundry and various (the various players) suggesting we should do the same for anthelmintics. The response was under whelming.

Even very well-informed users sometimes get tripped up when it comes to which product belongs to which drench group, which makes sensible drench rotation a bit harder (apart from not knowing which drench works on your property).

At a recent farmer meeting (Coolah, NSW), someone in the audience asked me why we don’t have drench group information clearly listed on the label – and I thought that maybe we should revisit this.   I think a colleague  (Gareth Kelly, UNE?) recently brought it up again as well.

Maybe I/we should have another crack at it….and maybe I shouldn’t give up so easily this time.


Why do the different stages of some tapeworms have different names?  

Some tapeworms have different names for the adult and larval stages.

For example, the adult stage of the ‘sheep measles tapeworm’ is called Taenia ovis. It lives in the intestine of dogs (the final host). However the larval stage, which occurs as cysts in the tissues of intermediate hosts (sheep, goats), is called Cysticercus ovis.

When these different tapeworm stages were discovered, described and named, it was not known at the time that they were different stages of the same organism. (This, at least, is my understanding).

Even when the life cycles of these worms were elucidated, the original names stuck, creating confusion for generations of students and others learning about parasites.

(In a previous life, I studied fungi: they are even more confusing).

Wrestling with Recurrent Infections  By Gayatri Vedantam and Glenn S. Tillotson


A friend/colleague brought this to may attention. It may be of interest. Although not specifically on worms, there might be some lessons here applicable to worm control.

"Clostridium difficile(CD) is evolving more robust toxicity, repeatedly attacking its victims, and driving the search for alternative therapies to fight the infection".

(SL: This brings to mind an unhappy incident when, as a new veterinary graduate, I prescribed ampicillin for a sick guinea pig. This is a big no-no, as penicillins cause CD in the gut of guinea pigs to overgrow, with the demise of the patient ensuing. Luckily the principal of the practice intervened in time).

"As infectious bacteria go, Clostridium difficile may be one of the most vexing for researchers, clinicians, and patients alike. It spreads from person to person by ingestion of the bacterium’s spores, which can not only remain viable for long periods of time outside of a human host, but can withstand most common disinfectants. Within the body, the spores can survive the acidity of the stomach, germinating in the intestines where the bacteria release toxins that wreak havoc on the bowel, causing severe abdominal pain and diarrhea. And while the proper regime of antibiotics usually eliminates the infection, residual spores can remain, and the bacteria can re-emerge with a vengeance weeks or months later."

(SL: By the way, dealing with spores is one of the limitations of alcohol-based hand rubs: see the NSW DPI Primefact on Zoonoses).

"Unfortunately, with rising rates of CDI in the United States and around the world, Smith’s experience is not that uncommon. Last year, CDI surpassed methicillin-resistant Staphylococcus aureus (MRSA) as the leading cause of hospital-acquired bacterial infection in the United States, and now also occurs in community settings with greater regularity, possibly transmitted through newly recognized sources such as raw and cooked food.2 To make matters worse, as many as 40 percent of CDI patients experience a recurrence of the infection,3.."

"Recent work shows that the increase in CDIs has been accompanied by the appearance of particularly virulent strains of the pathogen. And although antibiotic resistance is not yet a major therapeutic issue with C. difficile, some strains have started to show resistance to quinolones (Cipro and Levaquin) and some macrolide antibiotics (Biaxin),9 likely contributing to the selective pressures driving the evolution of the organism."

"Fortunately, novel therapies are being developed to combat even the most pathogenic strains of C. difficile. New antibiotics, for example, have already shown encouraging potential in defeating this dreaded microbe and reducing high levels of recurrence, while complementary approaches focus on preventively fighting back even before patients are infected. Though still in early stages, preliminary results are promising, and some experts believe that a combination of antimicrobial, immunological, and biotherapeutic techniques (SL: ie ‘ cultures’ (eg cud) to restore gut flora, as you might do in some calves etc…) may provide a breakthrough in the battle against CDI. Used appropriately—at the right times, and in the right patient populations—these new therapies should help reduce not only the incidence of the disease and the incessant recurrences seen with current therapies, but also alleviate the impact of CDI on human lives and economies."

"Almost a century ago Paul Ehrlich, the grandfather of chemotherapy, presciently warned of the emergence of organisms which would thwart our best medical efforts by developing means of resistance unless we “frapper fort et frapper vite,” roughly translated as “hit hard and hit fast.” When dealing with CDI, we must embrace this edict by choosing the right weapon for the right patient at the right time. Otherwise, Ehrlich’s predictions will continue to come true."

SL: some of the last para rings true for worm control too, don’t you think?


1. The larva of a bot fly, which infests the skin of various mammals, producing warbles, or the nasal passage of sheep, or the stomach of horses.

2. A person who likes to get up people’s noses   πŸ™‚

Etymology 1 Possibly a modification of Scottish Gaelic boiteag ‘maggot’  

Etymology 2 From bottom

Sources: wikipedia; personal experience.   πŸ™‚


From the  NSW DPI Primefact on Zoonoses….

Hand sanitisers, such as alcohol-based hand rubs (ABHRs), routinely used by health care workers, are particularly useful where there is no water. ABHRs compare very favourably with other hand cleaning methods against a range of pathogens, but they have their limitations. They are not recommended when there has been exposure to bacterial spores or protozoon oocysts, parasites, certain viruses (non-enveloped viruses such as rotavirus), when hands are visibly soiled with dirt or blood or other bodily fluids, or after using the toilet. In these cases, hand washing with soap and water is preferred. (Hand Hygiene Australia, 2010).

WRML: WormFaxNSW-May 2011 on-line, Quarantine drenching in UK; DAGFWA Farmnotes on Parasites; Carmichael et al on alpaca worms; van Wyk on tapeworms; Confidence Limits; etc

To WormMail (WRML) list (recip. undisclosed).       WRML.20110615    


The May edition is now online.


Many thanks to Craig Bratby (web guru, NSW DPI), Kath Cooper and colleagues (parasitology, EMAI (NSW DPI – Menangle) and Amanda Saunders and colleagues (Veterinary Health Research Armidale).

Quarantine drenching UK-style

This from David Bartram (<David.Bartram@pfizer.com>), with permission:

Hi Steve

  The quarantine treatment regime recommended by the SCOPS (Sustainable Control of Parasites in Sheep) group in the UK is monepantel and moxidectin administered sequentially. Treated sheep should be held off pasture (yarded) for 24-48 hours and then turned out on to dirty (worm infested) pasture. This is your option 2. below (see WormMail, 3 June 2011). By contrast to parts of Australia, MOX-resistance remains uncommon in Europe.

  Best wishes, David

Western Australian Farmnotes on internal parasites

As mentioned before, these have a new home;  http://www.agric.wa.gov.au/PC_92809.html

References on internal parasites of alpaca – Carmichael and others

I got these recently from Ian Carmichael. The RIRDC one is downloadable (see link below):

Β·        Carmichael IH (1996). Internal parasitism in alpacas in southern Australia. In, “Camelid Medicine and Surgery”. Proceedings of the Post Graduate Committee in Veterinary Science, 278, 327-339.  University of Sydney.

Β·        Carmichael IH, Ponzoni RW, Judson GJ, Hubbard DJ, Howse A and McGregor BA (1998). Studies on parasitism in alpacas in southern Australia. In,” Crossing the Boundaries” pp. 75-82.  Proceedings, International Alpaca Industry Conference, 9-12 July 1998, Fremantle Western Australia.

Β·        Carmichael IH (1999). Internal parasitism in alpacas in southern Australia. In, “Australian Alpaca Fibre – Improving Productivity and Marketing”. A report for the Rural Industries Research and Development Corporation, by W Hack, B McGregor, R Ponzoni, G Judson, I Carmichael and D Hubbard. Section 5 (pp 92-130). RIRDC Publication No 99/140.


Jan van Wyk – the last word on tapeworms ?

Quoted here with permission:

  Concerning the tapeworms, I quote from Steve’s newsletter:  "Dr Bruce Watt has just written a very nice article on this subject for his local (Bathurst) rag. This was discussed in a recent WormMail."

  From the above article, "SHOULD YOU DRENCH LAMBS FOR TAPEWORMS" by Dr Bruce Watt, the following:    " ….  As an aside, you will no doubt be fascinated to learn that a New Zealand lamb holds the record with 41 tapes."

  Well, I have news for Drs Watt and Love (!)  –  we don’t only play rugby in South Africa, but can apparently also compete in the field of the worms we breed here.

  In 1977 Ivan Horak and Johan Louw, at the time working for MSD, did 2 different surveys between 1968 and 1973 to estimate the seasonal cycling of helminths on irrigated pasture on what is now the highveld of Gauteng Province [[Horak, I.G. & Louw, J.P. Parasites of domestic and wild animals in South Africa. IV. Helminths in sheep on irrigated pasture on the Transvaal Highveld. Onderstepoort Journal of Veterinary Research, 44, 261-270]].

The surveys over   21  and  27  months, consisted respectively of 2 and 3  worm-free 4-8 month old tracer lambs per month grazed on pasture for a mean of about 33 days (hence with up to about 5 days of overlap between consecutive sets of lambs), whereupon they were slaughtered for worm recovery.

  In Survey 1 the highest mean number of Moniezia tapeworms recovered from the lambs was 202, and in Survey 2 the highest means were 408, 249, 156, 122, 74, 67, 56, 48 and 34.  The greatest number of Moniezia scolices recovered from a single lamb was 788 !  

  The short grazing period per lamb, possibly exacerbated by "overcrowding" of the worms in their hosts, resulted in most of the worms consisting only of a scolex and short string of strobilae, although some gravid worms were also found during the warmer summer months.  It was possible to identify the tapeworms to species level only in the case of the gravid individuals; in the others the identification to genus level was done from the morphology of their scolices (Horak, personal communication, 2011). On the other hand, in field trials on the efficacy of cestocides, we commonly encounter very large volumes of tapeworms also, but for the moment I cannot lay my hands on some examples of the volumes concerned.

  One of the main problems with estimating the effect of tapeworms on the production of young animals is that it is not possible to quantify the infection antemortem, with the result that the trials need to be done "blind", with the hope that the burdens will be high enough to give some hope of differentiation between treated and control animals if the worms are indeed deleterious.  

Secondly, of course is the difficulty of preventing contributory effects from nematodes which most commonly accompany the tapeworms.  In the trials of Horak and Louw, for instance, relatively large numbers of Haemonchus contortus,  Teladorsagia spp. and Trichostrongylus spp. were recovered from the lambs with relatively large burdens of Moniezia.

  So, to rub it in (!), it seems that the record books need to be adjusted somewhat as regards the tapeworm burdens of lambs ……….  "

Confidence Trick ?

I discussed confidence limits and worm egg count reduction test in a  recent WormMail.

The blurb below (for those without a life and ‘into’ statistics) is technically more accurate:

Confidence limits

After you’ve calculated the mean of a set of observations, you’d often like to give some indication of how close your estimate is likely to be to the parametric mean. One way to do this is with confidence limits, numbers at the upper and lower end of a confidence interval. Usually, 95% confidence limits are used, although you could use other values. Setting 95% confidence limits means that if you took repeated random samples from a population and calculated the mean and confidence limits for each sample, the confidence interval for 95% of your samples would include the parametric mean.
To illustrate this, here are the means and confidence intervals for 100 samples of 3 observations from a population with a parametric mean of 5. Of the 100 samples, 94 (shown with X for the mean and a thin line for the confidence interval) have the parametric mean within their 95% confidence interval, and 6 (shown with circles and thick lines) have the parametric mean outside the confidence interval.

Source: http://udel.edu/~mcdonald/statconf.html

Demise of lice detection test

Sadly, an excellent test is going to be withdrawn:

"The Lice Detection testing service that has been available at EMAI for almost 2 years. Due to the disappointing uptake of the test, we will be doing no further testing after 30 June 2011.

We know that quite a number of sample collection kits were requested but as yet not submitted to the laboratory.  Any unused sampling kits should be discarded. It is likely that some Sheep and Wool Officers and aligned staff have a number of these kits. Please be aware that any samples arriving after 30 June 2011 will not be processed.

We thank all those who have used the service or recommended the test to their clients.

Yours sincerely,
Garry Levot

Dr. Garry LEVOT
Principal Research Scientist – EMAI, NSW DPI

Nature’s Insecticide Dying?

"Since February, 2011, for example, we have been following reports of the spread of white-nose syndrome, a syndrome that has killed over one million bats in North America. 

This may not seem especially urgent until we consider that bats are “nature’s insecticide” – a single brown bat eats 600 insects an hour!  Tracking this disease is the only way to potentially slow its spread until better means are identified to treat or prevent it. {Unfortunately, in the meantime the agricultural industry will be using significantly more chemical pesticides to kill crop-damaging insects that the bats normally would eat}.

Large scale animal die-offs – bats, honey bees, monkeys, many varieties of birds and fish – can have serious implications for human and plant health, either immediately or down the road.  They may also signal a threat to other species including our own. As always, vigilance is our best strategy to minimize these threats."

Source: Promed June 2011