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ROUTINE WORM EGG COUNTS
Check your horse's risk of re-contaminating your pastures with redworm and roundworm eggs with a worm egg count.
Routine worm egg counts are recommended roughly every 3 months in adult horses to check the risk of pasture contamination from individual horses. This allows us to target treatments accordingly.
Worm egg counts provide a 'snap-shot' of your horse's potential parasite burden but cannot detect any migrating larval stages.
KEY INFORMATION
Here is some key information that you might like to know when it comes to getting a worm egg count carried out for your horse.
CHECK THE PRODUCT THEY WERE LAST WORMED WITH AND WHEN
To reduce the risk of false negative results, it is recommended that you wait a minimum number of weeks from administration of a wormer before getting a routine worm egg count carried out.
This time frame will depend on what drug you used. Below details the recommended number of weeks you wait based on the active chemical ingredient used.
HOW TO TAKE A SAMPLE
A dung sample is required for a worm egg count. You should take multiple ‘pinches’ of dung from different areas in the pile. Ideally, if you are bringing a sample in store, bring as much as you can and our technician will homogenise the whole sample. This is to account for the distribution of the parasite eggs throughout a whole dung pile. If you’re preparing a sample for posting, you can mix a pile yourself and then select around 5-10g to send in the sample pot.
The fresher the better. If a pile has been passed overnight in the stable or field, the sample should be fine for collection and sending via post or bringing in-store. If there is a delay in you being able to get to us or posting the sample, please refrigerate the sample (double bag and label it if you’re putting it in the kitchen fridge!).
HOW DOES A WORM EGG COUNT WORK?
A worm egg count works by allowing any parasite eggs produced by adult worms that are present within a dung sample to float in a suspension. The number of eggs are then counted under the microscope and then multiplied by a number to estimate the total number of eggs per gram of faeces (EPG).
WHAT DO THE RESULTS MEAN?
The total number of eggs recovered are reported. If no eggs were recovered, the results are not reported as 0 just because no eggs were recovered, it doesn’t necessarily mean there aren’t any at all within your horse!
Horses are then classed as low, medium or high egg shedders. Those shedding low numbers are a low risk of recontaminating the pastures and those that are high shedders are at a high risk. It is recommended that any horse with a worm egg count of >200 EPG is dosed for the relevant parasite for which eggs were recovered.
Current evidence suggests that only 20-30% of horses harbour the majority of parasites, meaning we can treat a small proportion of horses with a wormer which controlling the majority of the parasite population. Reducing the amount of wormers we are using.
LIMITATIONS OF THE TEST
Worm egg counts can only give you a snapshot of your horse's potential worm burden. They cannot detect the numbers of individual adult and migrating larval stages. They are useful however to identify individual horses that shed the most numbers of parasite eggs in their dung. This allows us to target treatments to reduce the risk of re-contamination of the pasture with parasite eggs.
