By Deb Maxwell, ParaBoss Operations Manager

March 2016

Don’t bother testing all those combination drenches you might use, just test the WormBoss list of key single actives, pop the results in the new online calculator and you’ll estimate the efficacy of all combination drenches that contain those singles.

Gone is the dilemma of choosing from the many single and combination products available to test. Testing them all is too expensive and just testing combinations doesn’t tell you the efficacy of each of the actives.

With this method you test nine single actives, plus an undrenched group to use as a comparison, and you gain calculated results for a further 14 types of combination drenches, representing many more commercial drench products. That’s great value.

Also, if a new combination product is released on the market, using the existing drench actives, you won’t need to test it if you have already tested its ingredients.

An incredibly easy online version of the Combination-Drench Efficacy Calculator is now online, providing an alternative to the previous excel spreadsheet version.

Simply open the web page and type in your efficacy results for the single actives and the estimates of the efficacy of combinations appear automatically. This prints onto a single page to keep as a record.

WormBoss recommends the following key single actives to be tested:

• levamisole (LV)
• albendazole OR fenbendazole OR oxfendazole (one of the ‘white’ or BZ drenches)
• abamectin (ML)
• moxidectin (ML)
• naphthalophos (OP)
• closantel (SA)
• monepantel (AD)
• derquantel (SI) + abamectin (ML) (as derquantel alone, is not available for testing).

Drench Resistance Tests are critical for a successful and sustainable worm control program. Using effective drenches:

• stops worms from slowing growth of stock
• prolongs the time until the next drench
• decreases scouring and dag
• halts clinical effects of worms
• keeps drenches working for more years on your property

Drench Tests involve the sorts of things you can already do:

• pick out an even line of sheep
• drench groups of them with different products
• tag the sheep so you can identify each group again

You also need to collect dung directly from each individual sheep in the test 10–14 days after they were drenched. Maybe you haven’t done this before, but it’s not complicated.

The biggest tip for doing Drench Tests is to do it with a friend.

The drenching, tagging and dung collection processes, while not difficult, are fiddly because of the various groups of sheep, and are best done with two people.

One person manages and passes the drench, tags or sample bottles for the particular group of sheep while the other does the drenching, tagging and dung collecting.

Encourage a friend or neighbour to also do a test so that you can help each other out.

Step-by-step instructions for Drench Tests are found here.