By Becca Price
Last year the practice invested in a new Ovacyte Worm Egg Counting (WEC) Machine, which uses AI to look at a sample, identify and count the number of worm eggs and Cocci present. Previously to this each sample was looked at through the microscope by one of the vets or lab techs and counted manually – quite a laborious process! When carrying out WECs we can detect a number of different worms: Strongyle-type, Nematodirus, Moniezia, and Cocci. Testing for Lungworm and Fluke can be done in house but are run differently. One of the good things about utilising such technology is the ease of data collection, allowing us to look for trends through the seasons, but also on individual farms.
During the warmer months, when we would traditionally expect parasite burdens to be higher and of more significance, we would recommend a pooled WEC of each group of animals every 4-6 weeks and then treating if needed after discussion with your vet. This allows us to treat groups of animals as needed but also allows us to build up an idea which pasture is clean and dirty.
As we try and reduce the number of anthelmintic treatments needed – to reduce the likelihood of resistance developing, protect the environment and save some money! – understanding the “risk” of different pasture is increasingly important to develop a more holistic approach to parasite control. We are increasingly carrying out pasture mapping. Depending on what each parcel of land has been used for (youngstock, arable rotation etc) we can categorise them into high, medium or low risk grazing. This can be represented visually by colour coding a map of the grazing you have available to help decide where certain groups of animals are going to graze next.
An example of this would be using a field not grazed by sheep in the last year and was instead a new ley after forage or arable crop, to graze your most vulnerable animals – young lambs.
The graphs represent all WECs done over the last 14 months (note – alpaca and goat WECs will be included within the sheep graph) and as would be predicted we see significantly lower WECs over the colder winter period around about January/February.
This summer we have seen some very high WECs, especially in the small ruminants. This is likely a combination of the warm dry weather, lack of grass growth and overgrazing. 80% of parasites are found in the first 5cm of grass, so it’s clear this could have been a contributing factor with the summer we had!
Some of the counts are off the top of the chart – sometimes this can be an indicator of Haemonchus, or Barber Pole worm. Haemonchus is a blood-sucking parasite which can cause a severe anaemia leading to severe losses. Up until recently we look at the results in context to raise suspicion – very high WECs, lack of scour and pale mucus membranes, or the samples could be sent externally. A recent upgrade to the Ovacyte machine allows us to differentiate between Strongyles and Haemonchus, enabling us to make these diagnoses with more certainty once a high Strongyle count has been seen.
As the graphs show, last year WECs remained high well throughout Autumn and start of Winter, so it is important to remain vigilant. The Winter is a good time to meet with your Vet and review parasite control plans before lambing begins in the Spring. Please get in touch with the practice if you would like guidance on creating parasite control plans.
Graphs showing WEC results from our West Stour in-house lab
To read the full newsletter please go to our Monthly Newsletters page.
