According to experts at Pfizer Animal Health, they are alarmed about the results of a recent survey which has shown that half of all horse owners are not worming their horse or pony correctly for encysted small redworm.
"It is one of the life stages of small redworm which are the most common worms found in horses today," said Wendy Talbot, Pfizer's vet advisor.
"Encysted small redworm may account for up to 90% of the redworm burden in the horse and can pose a very serious health risk. It's important to make sure that they are treated properly during late autumn or winter. However, the new data has alarmingly revealed that this isn't happening in around half of all cases."
The survey, which was conducted as a part of the National Equine Health Survey (NEHS) in May 2012, showed that only 50% of 1095 respondents wormed their horse with an effective product for the control of encysted small redworm. The remainder either used a product they incorrectly thought treated encysted small redworm or simply didn't worm their horse or pony at all to control the parasite. The most common reason given for not treating for encysted small redworm was that the horse had had a clear faecal worm egg count.
"Encysted small redworm won't show up in a standard faecal worm egg count – even if the horse has shown a negative or low count it could still be harbouring several million encysted small redworms, which can present a potentially fatal health risk to the horse," said Wendy.
"Encysted small redworms can remain dormant inside a horse for up to two years, but usually develop and emerge from the gut wall all at the same time in the early spring. In severe infestations mass emergence can lead to a disease syndrome known as 'larval cyathostominosis', causing diarrhoea and colic with up to a 50% mortality rate.
"It is imperative to use a wormer containing moxidectin or fenbendazole five-day course, licensed to treat encysted small redworm. It is important to remember that there is now widespread resistance to fenbendzole in parasite populations4 whereas moxidectin has been shown to be effective against benzimidazole resistant worms and has a 13-week recommended dosing interval."
For further information speak to your vet, SQP or visit www.wormingyourhorse.info