September 6

Managing Worms Means More Than Just Drenching

With Virbac Australia

We can no longer manage worms just by using drenches. Pasture management is key.

Monitoring worm egg counts and drenching only when required reduces the exposure of the parasite to the drenches that still work. By doing a faecal egg count reduction test (FECRT) every 3-5 years, we know what drenches still work against the parasites in our animals.

Using an effective drench like Tridectin®, reduces the number of worm eggs deposited on pasture by treated animals. The difference between 98% efficacy (average Tridectin efficacy), and 93% efficacy (average Abamectin-triple drench efficacy) results in 3.5 times more resistant eggs on pasture.1 With a worm egg count of 1200 eggs per gram of faeces, a mob of 250 ewes (70 kg each) will produce 42 million more eggs per day if treated with the drench that’s only 93% effective.

The more we use the same drench, we inadvertently select for resistant worms that survived the drench. To delay the onset of resistance, we’ve increased the use of combination drenches. Unfortunately, most of the drenches used contain Abamectin (table 1).

Table 1

Table 1

Increasing the selection pressure for resistance against this molecule. All actives that are proven to still work should be included in the program. Using the same active (e.g. Abamectin) repeatedly should be avoided, however. Including Tridectin® is a smart choice, as it is the only three-way combination drench containing Moxidectin that controls reinfestation with barber's pole and small brown stomach worms for 14 days due to Moxidectin's persistency.

Moxidectin-single-actives (e.g. Cydectin Long Acting Injection for Sheep) can be added to the program, if used concurrently with a primer.

For more information visit au and contact your local area sales manager from Virbac to assist you to design your worm management program.


Find out more here


Agriculture, animal health, Pursehouse Rural, Seasonal

You may also like

{"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}

Get in touch

0 of 350