Are Worm Egg Counts Reliable for Monitoring Horse Health?
Worm egg counts have become a crucial tool in the management of equine health, particularly in the context of parasite control. However, the reliability of these counts can vary depending on several factors. In this blog, we will delve into the details of how worm egg counts work, their limitations, and their importance in maintaining the health of your horses.
What is a Faecal Worm Egg Count (FWEC)?
A faecal worm egg count (FWEC) is a diagnostic test that involves analyzing a sample of a horse's faeces to determine the presence and quantity of worm eggs. This test is typically performed during the grazing season (April-October) and is essential for monitoring the parasite burden in horses.
How to Collect a Faecal Sample
To ensure accurate results, it is crucial to collect the faecal sample correctly. Here are the steps:
- Collect the sample while it is still warm using a glove and place it into a container or clean freezer bag.
- Take samples from several faecal ‘balls’ within one pile of droppings to ensure the sample is representative.
- Label the container with your horse’s name, your surname, your postcode, and the date the sample was taken.
What Do the Results Mean?
The results of a FWEC are given in eggs per gram (epg) of faeces. Here is a general interpretation of the results:
- Less than 50 epg: Indicates very low or no worm eggs present.
- Between 200 epg and 1175 epg: Suggests a moderate worm burden, and treatment may be necessary depending on the overall health of the horse and pasture management.
- Over 1200 epg: Indicates a high worm burden, and treatment is usually required.
Limitations of Faecal Worm Egg Counts
While FWECs are valuable, they are not without limitations:
Not all parasites are detected
FWECs do not identify pinworms, bots, tapeworms, or encysted small redworms. For example, tapeworm eggs may not always be present in the faeces, even if the horse is infected.
Does not account for immature worms
Immature worms that are not yet laying eggs will not be detected by a FWEC.
Variability in techniques
Different methods for counting worm eggs can yield varying results. For instance, techniques like McMaster, Mini-FLOTAC®, and simple flotation have different performance parameters.
Importance in Monitoring Horse Health
Despite the limitations, FWECs play a significant role in maintaining horse health:
Targeted treatment
By identifying horses with high worm burdens, you can target treatment to those that need it most, reducing the risk of developing resistance to anthelmintics (wormers).
Pasture management
High worm egg counts can indicate the need for improved pasture management to reduce the overall parasite burden.
Preventing health issues
Regular monitoring can help prevent health issues such as colic, weight loss, and poor coat condition, which are associated with high worm burdens.
Overcoming Resistance to Wormers
One of the primary concerns in equine health is the increasing resistance to anthelmintics. Here are some strategies to help mitigate this issue:
Regular monitoring
Conducting FWECs at regular intervals ensures that only horses with significant worm burdens are treated, reducing the selective pressure for resistance.
Fecal egg count reduction tests
These tests assess the effectiveness of a wormer by comparing the egg count before and after treatment. If the egg count does not reduce by 80% or more, it may indicate resistance to the drug.
Conclusion
Faecal worm egg counts are a reliable and essential tool for monitoring the parasite burden in horses, despite some limitations. By understanding how to interpret the results and integrating FWECs into your equine health management plan, you can ensure that your horses receive targeted and effective treatment. This approach not only improves the health and well-being of your horses but also helps in managing the risk of resistance to anthelmintics.
For more resources on maintaining the health of your equines, visit our Everyday Horse Vitamins & Supplements Collection and check out our Stable Rugs
