WRML. WormFaxNSW-Feb 2012 now online

WormFax NSW – Feb 2012 is now online

Results, map and notes:

http://www.dpi.nsw.gov.au/aboutus/resources/periodicals/newsletters/wormfax

 

Aftermath

As discussed before, unseasonably wet conditions over the last several months in much of NSW means many paddocks are very wormy. Flow on effects from this will extend into Spring and beyond.

With the onset of colder weather, some of the more cold sensitive internal parasites (eg eggs of Haemonchus, Fasciola) will not be able to complete their life cycle (in winter months in colder areas), BUT they have produced plenty of infective stages (eg third stage (L3) larvae in the case of roundworms) on pasture up until now and many of these will make it through to spring, frosts notwithstanding.

What can you do?

* Keep up regular WEC monitoring (WormTest). Don’t guess, WormTest.

* Prepare low worm-risk paddocks for spring lambing. (You can’t rely on long-acting drenches for ever).

* When/if you drench, check that the drench worked i.e DrenchCheck ( WEC 10 days (sheep) or 14 days (cattle) after a drench, preferably matched with a WEC on or just before the day of drenching).

Get advice on when to DrenchCheck in the case of mid-length (eg Cydectin oral) and long-acting (eg Cydectin LA inj; capsules).

* On ‘flukey’ (Fasciola hepatica) farms, give the strategic April/May fluke drench , using a triclabendazole-based drench ( Nitromec(R) is another option in cattle). The April/May fluke drench is the most important fluke drench of the year. It’s important to use a ‘high efficiency’ flukicide at this time. Rotate to a flukicide from a different group if you can if drenching again in Spring.

* Move weaners (cattle, sheep) into low worm-risk paddocks with good tucker.

A case from Carinda (Slattery)

Shaun Slattery (Senior District Vet, North West LHPA) told me of this case:

Haemonchosis in lambs from a property near Carinda (Macquarie Marshes area). A lot of rain in January. Moderate signs of haemonchosis. 15 dead out of a few thousand. No signs of diarrhoea and sheep in fat condition.

Sample collected by Ranger from rectum of dead lamb, but ~ 15 hours post mortem. (Delay in collecting may have increased egg count (epg)????).

Notwithstanding the above, the lab reported a WEC of ~ 67,000 epg.

Investigators were surprised by the count given the relatively low mortality rate. (Yes fellow epidemiologists, I know this strictly is a proportion not a rate! At least I don’t confuse ‘incidence’ with ‘prevalence’ 🙂 SL)

Larval differentiation: Haemonchus: 63%, Trichostrongylus: 27%, Ostertagia (Teladorsagia): 10%. Such large scour worm counts were considered surprising given the absence of scouring (diarrhoea).

Another case of high WECs: https://wormmailinthecloud.wordpress.com/2010/03/17/redux-sky-high-counts-at-bre/

This one was mostly Trichostrongylus (~60,000 epg), which I think is amazing. As to Haemonchus, the highest I have come across is ~ 80,000 epg. Haemonchus of course is somewhat more fecund than scour worms, and Haemonchus – in pure infections anyway – tends to constipate (small,dry pellets) which I guess increases the egg count still further.


Regards,

SL

WRML. update on drench resistant cattle worms in Australia

WRML 20120329 update on drench resistant cattle worms in Australia

Further to earlier WormMails on this subject, attached is a PDF of some of the slides I currently use for farmer talks.

Australian cattle producers perhaps looked smugly at sheep producers, and (‘Kiwi’) cattle producers across the Tasman, who had problems with worms becoming drench resistant.

Until the last decade or so, the reports of cattle worm resistance in Australia were few and seemingly inconsequential (eg report(s) of BZ resistant T.axei by Eagleson and others).

Now the landscape has changed.

There are for example, published, peer-reviewed reports of cattle worm resistance by Lyndal-Murphy and others (Queensland) and Rendell (western Victoria).

As well as these, the attached PDF contains (previously) unpublished information (used with permission) from P I Veale (north east Victoria) and most recently, preliminary results of a survey in Western Australia (J Cotter and others. Cotter and Besier will present the full results of this survey at the Australian Veterinary Association Conference in May this year (2012)).

Regards

SL

Links to some previous ‘WormMails’ on drench-resistant cattle worms:

https://wormmailinthecloud.wordpress.com/2011/11/18/wrml-more-on-drench-resistance-of-cattle-worms/

https://wormmailinthecloud.wordpress.com/2010/07/13/triclabendazole-resistant-liver-fluke-in-cattle-on-the-nsw-south-coast/

https://wormmailinthecloud.wordpress.com/2010/07/01/check-your-cattle-drench/

https://wormmailinthecloud.wordpress.com/2010/05/26/test-for-macrocyclic-lactone-cattle-pour-ons-at-14-days-post-drench-was-re-cattle-drenches-resistance-and-rotation-a-conversation/

http://www.dpi.nsw.gov.au/aboutus/resources/periodicals/newsletters/turning-the-worm [ Turning
the Worm
(Issue 22, Dec 2007)
]

Love S.20120229-cattle worm resistance slides[PDF].pdf