Sheep, Goats & Alpacas

Worm Egg Counts

Worm egg counts (WEC) are an accurate method of checking the worm status of a mob/ group or individual animals. The test provides an indication of the type and size of worm burdens present so that animal owners can choose whether a drench is required and minimise the use of drenches when they are not required.

The test determines the number of eggs in a sample of faeces and is expressed as ‘eggs per gram’ (EPG) of faeces. For small ruminants the significant worm species our worm egg counts are able to detect include;

  • barbers pole worm (Haemonchus contortus),
  • small brown stomach worm (Teladorsagia circumcincta),
  • black scour worm (Trichostrongylus spp),
  • large-mouthed bowel worm (Chabertia ovina),
  • nodule worm and large bowel worm (Oesophagostomum spp)
  • small intestinal worm (Cooperia spp)
  • thin-necked intestinal worm (Nematodirus spp)
  • tapeworm (Moniezia)
  • coccidia (Eimeria spp)

Individual Worm Egg Count (McMaster)

An individual WEC gives you 15 individual counts from each of the wells in our sample collection tray in the Dawbuts WEC test kit. Eggs per gram are calculated for each of the 15 samples to show the highs, lows and distribution of eggs in a mob. This provides valuable information on existing (adult) worm burdens and paddock larval populations, if samples were collected just prior to drenching, or, for anthelmintic efficacy if faecal samples were collected 10-14 days post drenching.

Pooled Worm Egg Count (McMaster)

In this test, 15 samples will be divided into 3 pools with each pool representing 5 animals. The pooled test provides averages for worm burden in the mob however it does not provide information on the variation of worm burden within your herd. Some information on worm distribution in the flock can be obtained using pooled samples, and is conducted at a lower cost than individual counts.

Larval Differentiation

As eggs of the significant worm species appear very similar during worm egg counts, a larval culture will be required to identify individual species. Determining the species present in your worm egg count can assist you in choosing the best drench.

Fluke Test

This test will determine if liver fluke is present in your mob. Liver fluke can severely impact sheep production, with negative implications on wool quality, lambing percentages and lamb growth rate. If the intermediate host, the aquatic snail, is present on your property it is recommended that a fluke test is conducted.

Drench Resistance Tests

This test is used to assess how effective certain drenches are against the worms present on your property. At Dawbuts, a standard drench test consists of 3 drench groups plus one control (untreated) group, however additional drench test groups can be added. The test requires 15 sheep per drench active you are testing and an additional 15 sheep for the control group.

Results will provide information as to whether the worm species present on your property are either resistant or susceptible to the drench actives you submitted. A drench is considered effective when worm egg counts are reduced by 98% or more. These results will provide you with the knowledge to make informed decisions on which drench is best to use on your property. This test should be conducted every 2-3 years.

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