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(08) 9071 5777

Parasitology - Faecal worm egg counting, drench resistance testing & advice

Faecal Worm Egg Counts – Why and When.

Worm Egg Counts are a very useful tool. WECs conducted at strategic times will be helpful for a number of reasons:
1. Prevent unnecessary drenching saving both time & money
2. Reduce the development of drench resistance
3. Reduce the worm burden on the pasture
4. Increase productivity by recognising sub-clinical disease
5. Reduce the risk of a worm outbreak resulting in sheep losses
6. Give an indication of the effectiveness of a drench

The WEC is a simple test. It involves the producer collecting 10- 20 individual faecal samples from a mob of sheep. From these samples we can determine a mob WEC average. Based on the time of year, class of sheep, weather conditions & condition of the sheep, a decision to drench or not is made.

WEC should be conducted at the following times:

1. Pre-lambing
2. Pre-marking (ewes)
3. Pre-weaning
4. Pre first summer drench. Weaners and hoggets should be drenched at the start of summer. Older sheep should be monitored to see if this is required.
5. Autumn before the break of the season. If a drench is required this will reduce contamination of winter pastures. Lambing ewes that did not receive a summer drench should be drenched by early April.
6. Any time that sheep are scouring or not performing as well as expected.

Drench Resistance Testing

Drench Resistance is a significant problem in the management of worms in sheep. Knowing the drench status of your property is important as it ensures that drenches used are effective. Using drenches that have poor efficacy promotes further resistance. The more resistance there is on a property the less drench options available.
A Drench Resistance Test (DRT) should be conducted using undrenched weaners.

Click here for detailed instructions on how is a DrenchTest is conducted.
A number of drenches can be tested in a DRT. The drenches we test for will depend on previous results and the worming history of the property.
At Swans Veterinary Services we can help you set up your DRT.

Contact Us

Swans Veterinary Services

Lot 83 Shelden Rd

Esperance WA 6450

Monday to Friday 8am to 5:30pm
Saturday 8am to 12noon

Phone: (08) 9071 5777