In this issue
Haemonchus review paper – Emery, Hunt, Le Jambre
Products for worms – ebb and flow
The August issue is now on-line:
Haemonchus – review – by Emery and others
Haemonchus contortus: the then and now, and where to from here?
David L. Emery, Peter W. Hunt, Leo F. Le Jambre. Int Journal Parasitol 2016
Haemonchus contortus (Barber’s pole worm or ‘‘BPW”) is the nematode ‘‘nemesis” of small ruminant production systems in tropical and subtropical regions of the world. Its reputation derives from a combination of high fecundity and a short generational interval that provides an enviable developmental plasticity for adaptation or resistance to control measures.
This review critically examines the historical and current literature on the host–parasite–environment interaction for H. contortus, particularly in sheep, to highlight changes in parasite distribution and ecology on pasture, changes to the seasonal inhibition of fourth stage larvae and the most appropriate models to identify protective responses and assess
The review also proposes pathways to bring host genetics to fruition and avenues where
advances in the parasite genome may complement control measures.
2016 . Published by Elsevier Ltd on behalf of Australian Society for Parasitology. This is an
open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
https://www.ncbi.nlm.nih.gov/pubmed/27620133 (Thanks GAK).
Products for worms – ebb and flow
Haemonchus dipstick test – no longer available
‘Merial can confirm they will no longer supply the Haemonchus DipstickTest. Developed in conjunction with the Sheep CRC, this test provided a rapid assessment of Barber’s Pole Worm infection. However, farmers have preferred to use faecal worm egg count tests. This has removed the demand for the Dipstick test. Farmers who want to continue to use this test should still be able to find supplies at a local chemist.’ (GAK).
(The test uses test strips (commonly used in diagnostic testing by vets and medical doctors and others) that detect ‘occult’ (hidden) blood in faeces – by detecting haemoglobin (Hb). The most common reason for Hb in faeces in sheep is Haemonchus. _Ed.)
More information on this test: http://www.wormboss.com.au/tests-tools/tests/assessing-worms.php
Organophosphate (OP) drenches
Australia has had OP drenches for sheep (most of the time) since at least the 1960s. One of the early ones available was naphthalophos (aka ‘naftalofos‘), marketed by Bayer, for the most part as Rametin (Rametin H, Rametin HLV etc).
At various times there have been others, e.g., triclorphon (Neguvon (Bayer)), pyraclofos (吡唑硫磷, пираклофос; combined with albendazole), in Colleague (Coopers). Naphthalophos (alone or in combination with other actives) has been the most used OP in Australia for control of gastrointestinal nematodes in sheep, under various brand names, for example: Rametin (Bayer), Combat (Virbac) and Napfix (Jurox), (and “Pole Vault”!).
However, OP drenches are becoming thin on the ground.
Combat (naphthalophos, Virbac) – no longer available
Virbac advised me in August 2014 that Virbac had made a decision to discontinue Virbac Combat (naphthalophos). (MB)
Rametin (naphthalophos, Bayer) – no longer available
Bayer was having problems accessing the active for Rametin (see here) but have recently advised me that Rametin is no longer being produced. ‘There might still be stocks out in the market as the last batches were released in the last 3-4 months but after that there will be no more produced. It has been impossible to source some of the key ingredients so production has no longer been possible.’ (DD’O)
Neguvon (triclorfon, Bayer) – no longer available
Neguvon has been used for a long time in various animals (In the 1970s, for example, we were were worming horses by stomach tube, using a mix of piperazine, thiabendazole; and Neguvon (the latter for bots)). For a while there was a permit allowing the use of Neguvon to control Haemonchus in goats in Australia However this permit has expired and I believe Neguvon is no longer produced. (NC, DD’O) Trichlorfon still appears as an active ingredient of various registered products, including, for example, horse wormers (as a boticide) and insecticides.
Colleague (pyraclofos+albendazole, Coopers)
This was on the market for a while, then went off the market due to mortalities on some properties, then came back, but has now gone again. (Thanks JM)
OPs tend to have narrower safety indexes (margins) than many other drenches but, at the same time, most deaths tended to be clustered on a smaller number of properties, with many if not most users having few if any problems at all.
A good thing about the OPs is that it has given us another active, and gave good worm control -although generally ‘mid-spectrums’ – especially when used in combination with other, unrelated actives.
Napfix (naphthalophos+abamectin+albendazole, Jurox) -currently unavailable
I hope it and/or other OP-based drenches comes back, for the sake at least of farmers, so they have another option.
Zolvix Plus (monepantel + abamectin, Elanco) – released in NZ
This has been released in New Zealand. (Thanks PM)
Drenches – the most important thing(s)?
Two things actually…
- don’t rely on drenches alone.
How not to: http://www.wormboss.com.au/programs.php
- find out what drenches work on your farm. That’s the first thing to work out when thinking about drenches, not whether to use short- or long-acting, or whether to rotate or use combinations, or what brand to get etc. See: http://www.wormboss.com.au/tests-tools.php