Winter Worms

Winter is normally the time of year when we think much less about faecal egg counts and more about treating encysted small redworms and bots. Many horses on Intelligent Worming programmes will also have an annual tapeworm treatment combined at the same time so winter is normally much more about administering chemical treatments. 

Traditionally, faecal egg counts have not been used much throughout the winter because the main parasite we are looking to detect, the small redworms, encyst in the gut wall and at least 90% would normally lie dormant over the winter months.  During the cold weather the parasites need to find a way to survive. They are exposed to the cold conditions on the pasture and once ingested they then encyst and they remain in the gut wall for a period of time which can be for up to two years.

Horses that join Intelligent Worming programmes throughout the winter are always tested, this is because if they have a high worm burden it will be detected regardless of outside temperatures. Intelligent Worming horses with high burdens are also tested to ensure the effectiveness of chemicals.

Intelligent Worming use the leading ScientifEQ laboratory to conduct their the faecal egg counts, they have reported that due to the mild winter experienced this year the egg count results have shown a marked variation to the norm for the time of year. 

Over the winter months you would expect to see very low or clear faecal egg count results due to the majority of small redworms being encysted.  From December 2011 to end February 2012 we have tested a similar number of faecal samples each month and interestingly the results for each month have followed similar patterns. For example, in every 10 samples tested each month 3 had high results, 4 medium results and 3 low. In previous years we would expect no more than one in 10 samples to have a high reading, perhaps 2 or 3 medium and the rest low.” reports Simon Daniels, Veterinary  Diagnostic Services Manager, ScientifEQ.

What this indicates is milder wetter winters mean that there is more worm activity throughout the winter months because fewer small redworms are encysting. This also means that faecal egg counts are becoming a much more valuable tool all year round as the weather evolves so do the worms.