WormMail(WRML).2015-04-23. Wormfax. High Haemonchus counts. Targeted treatment.Snapshot-lamb industry+DPI input.WA threatens secession. In this issue:
- WormFaxNSW March 2015
- A case for Worm Testing and DrenchChecks (Jim Kerr) incl. Resistance Survey (Playford et al)
- Targeted / selective treatment – some thoughts (Johann Schröder)
- Snapshot of Australian sheep and lamb industry (+ DPI input) – MLA report
- Western Australia threatens to secede
WormFaxNSW-March 2015 For more information on WormFax – and for the full results – go here: http://www.dpi.nsw.gov.au/aboutus/resources/periodicals/newsletters/wormfax In the table below are some highlights: Table. Highest Sheep WormTest results around the traps – NSW, March 2015
|Lab||Area of NSW(LLS, former LHPA etc)||Sheep class||WormTest Mean egg count (strongyle)||Range||Haem||Trich|
|V||Northern New England||Ewes||12368||600-21600||100%|
|E||Central West||Mer. wethers||14600||100%|
|E||Central Tablelands||Hogget ewes||3620||1640-5600|
Notes: E=EMAI=Elizabeth Macarthur Agric. Institute (Menangle). V=VHR=Veterinary Health Research (Armidale). LLS=Local Land Services. LHPA=the former Livestock Health and Pest Authorities (now part of LLS). Haem=Haemonchus (barber’s pole worm). Trich=Trichostrongylus (black scour worms). Tel=Teladorsagia (small brown stomach worm. Larval differentiation results for Tel. not included: they were found in just a couple of cases and at 1-2%). There was a smattering of positive Fasciola (liver fluke) egg counts, mostly through tablelands districts.
Bear in mind that, for most ‘flukey’ farms in NSW, April-May is the single most important time for a strategic fluke drench. A standout in the results for March was some high Haemonchus egg counts in various parts of the state. There was very good rain in many parts of NSW in December and January, before returning to the trend of below average rain in February and March. It would appear the good early to mid-summer rain was enough to kick Haemonchus along. But again the perennial question: how many got caught because they do not do regular WormTesting, and how often was a worm problem exacerbated because drench efficacy is so often left unchecked? Note the high count (mean of 4448) from the South Coast LLS where the larval culture was dominated by Trichostrongylus. Sometimes Trichostrongylus can produce reasonably high WECs; not high by Haemonchus standards (but, WECs in that WormTest did range up to 18400!), but reasonably high nonetheless. Young and older players have been caught by this before: a high-ish WEC and have eschewed a larval culture, assuming Haemonchus to be the cause, and have opted for a narrow spectrum drug like closantel.
Now, speaking of high WECs: the highest I recall for Haemonchus was ~ 121,800 epg (EMAI vet Mel Gabor handled that case), but even more spectacular in a way was a case out Bourke way, handled by field veterinarian Kylie Greentree (now at greener pastures in the Hunter). In Kylie’s case, the epg was ~ 60,000 – BUT!! – it was Trichostrongylus (yes, the larval differentiation result was double-checked), not Haemonchus. More details here: https://wormmailinthecloud.wordpress.com/tag/dpi-role-in-major-award/
Case study – a good reason to WormTest and DrenchCheck Dr Jim Kerr, Wingham-based District Veterinarian for the Hunter Local Land Services, told me of deaths he investigated in 6-8 month old Dorper lambs in the Gloucester area of NSW. Five out of 13 lambs died in February. They had been drenched with Q-Drench® (abamectin + albendazole + levamisole + closantel) in February, then again on 15 March. Two more died after the mid-March drench and another two were pale. They were mostly set-stocked, i.e. mostly grazed the same paddock. Faeces from 8 lambs were submitted to the lab on 7 April, approximately 3 weeks after the last Q-Drench. The average strongyle egg count was 17,760 eggs per gram of faeces (epg), with individual counts ranging from 80 to 70,000 epg. The prepatent period for Haemonchus can be as short as 18 days, and these samples were collected about 23 days post-drench, but I think it can be safely assumed (drench maladministration etc. aside) that Haemonchus on this property is resistant even to Q-Drench and each of its constituents. All this of course could have been simply avoided through regular WormTests and periodically checking drench efficacy with a WormTest after drenching (DrenchCheckDay10). Although called Homo sapiens (‘wise man’), we humans are not always super-smart. Consider this graph below, a partial summary of a survey of drench resistance in Australia published by Playford and others in December 2014. Figure. Percentage of tested sheep farms with drench resistance (Australia, 2009-2012)
Notes: BZ=benzimidazole, ‘white’. LEV=levamisole, ‘clear.’ MPL=monepantel (‘Zolvix’, an ‘AAD’. No resistance detected).The macrocyclic lactone (ML, ‘mectin’) drenches are: IVM=ivermectin, ABA=abamectin, MOX=moxidectin. BZ/LEV etc. are combination drenches. CLOS=closantel. *Less than 50 usable drench tests for this drench. ‘Resistance’ here means the worm egg count reduction after treatment was <95% for one or more of Haemonchus, Trichostrongylus or Teladorsagia species. Reference: Playford MC, Smith AN, Love S, Besier RB, Kluver P and Bailey JN, 2014. Prevalence and severity of anthelmintic resistance in ovine gastrointestinal nematodes in Australia (2009-2012). Aust Vet J 2014; 92: 64-71. Consider the graph and the case study: ‘good reason to do regular WormTesting and DrenchChecks, don’t you think?
Targeted / selective treatment of sheep – some thoughts from Dr Johann Schröder “Thank you for another informative and thought provoking WormMail. Lewis’ piece on targeted selected treatment in the SRZ (summer rainfall zone) set me thinking. After many years as a successful livestock veterinarian in the Eastern Freestate (South Africa), Francois (Faffa) Malan was working for a pharmaceutical company in the late 1980s / early 1990s. He investigated a drench efficacy complaint in the Eastern Transvaal (Mpumalanga province on today’s map of the country) and discovered a big Haemonchosis challenge, but also fairly solid resistance to most chemicals available at the time. In order to reduce the producer’s reliance on chemicals, he suggested treating only the worst affected animals and selected them on the basis of their degree of anaemia, judged by the colour of their conjunctivae. This method seemed to halt further mortalities, saved the farmer a fair bit of money in chemicals and didn’t result in undue production losses. To underpin his recommendation with some scientific rigour, he proceeded, with the help of Gareth Bath (at the time professor in production animal medicine at the Onderstepoort vet school) to produce a set of photographs of graded conjunctival colouring. Thus was the FAMACHA (FAffa MAlan CHArt) born. I sat in the audience of the sheep vets conference in Armidale in 1997 when Gareth presented this idea, which was promptly rejected by the Aussies, because it was too labour intensive. The labour intensity of the technique remains, because animals need to be FAMACHA’d regularly in summer to avoid acute large scale mortalities. But it is also true that in a country where most sheep production occurs in a summer-dominant rainfall zone (the WRZ (winter rainfall zone) in South Africa is confined to a narrow coastal strip stretching about 1,000 km eastwards from Cape Town), FAMACHA has provided some measure of relief to sheep producers blighted, as we are, with drench resistance. All the best Johann Schröder” Lewis’s piece can be found here: https://wormmailinthecloud.wordpress.com/2015/04/14/wrml-2015-04-14-partial-flock-treatment-in-summer-rainfall-areas-aus-devil-in-the-detail-new-tech/
Snapshot of sheepmeat and other industries by MLA – and NSW DPI’s role MLA has published an interesting and well-presented snapshot of the lamb industry. It’s worth a read. http://www.mla.com.au/files/edcbf4da-3cf0-4859-9712-a475010b8dae/MLA_Real-Sheep-Prices-Publication_09-04-15.pdf or http://preview.tinyurl.com/pd4vw32
One of the key points: “The birth of the specialised meat sheep industry in Australia assisted a recovery in prices after the wool crash, generating increased global demand for higher quality lamb”. NSW DPI, along with others, has played an important role in the development of the sheepmeat industry. Past and current employees of NSW DPI who were involved include:
Past: Bill O’Halloran, David Hall, Brent Mcleod, Barry McDonald, Chris Shands, Peter Holst, Geoff Duddy, Neal Fogarty, Andy Kajons, Alan Luff, Dave Harris. Doing research in support of the resurrection of the lamb industry, there was Arthur Gilmour in particular and also Kevin Atkins, who did early work on developing Lambplan.
Current: David Hopkins, Ashley White.
This is by no means a complete list of players, but some of those with whom DPI worked closely in this area were Arthur Gates, Laurie Thatcher, Ron Harris, David Kingham, Ian Johnsson, Gerald Martin, Rob Banks, various NSW lamb processors and producer groups.
Western Australia threatens to secede http://www.theshovel.com.au/2015/04/13/western-australia-threatens-to-secede-from-rest-of-reality/ SL, 2015-04-24