Exmoor Ponies - conserved by conserving


EPIC's guide to equine parasites

What's what in wormers

EFFECTIVE SMALL REDWORM CONTROL (also known as cyathostomes or small strongles)


By using a 5-day course of a febendazole-based wormer at the end of October/early November, (i.e. before the period of disease risk) encysted larvae acquired during the grazing season will be removed. This treatment can be repeated again in February to remove larvae acquired during the winter months. This will also help reduce the levels of infective larvae on the pasture the following spring.


A Moxidectin based wormer has an ability to kill encysted developing cyathostome larvae in a single standard dose. Studies have indicated that the ingredient Moxidectin, suppresses egg reappearance for up to 3 monthsand therefore leads to a long dosing interval for small strongyle control. Moxidectin based Wormers are also effective against large strongyles, ascarids, pinworms, stomach worms and bots.


Worms are an ever-present threat even during winter months. Worms can survive frost and snow so even a short time on pasture during winter months can be enough for horses to pick up a new infection. Used routinely throughout the winter months, lvermectin based wormers will reduce the risk of infestation. The interval between treatments can be up to 10 weeks and in a single dose it will give effectiveness against both larval and adult stages of the important parasites of horses, including small redworms. lvermectin based Wormers control parasites that are resistant to -based wormers. lvermectin based Wormers will also control bots when given as a single dose in the late autumn or early winter after the first frosts.



If your horse is stabled on straw or other products where mites can survive then this double dose twice a year to ensure adequate control of tapeworm infestations. Once a year (late September/early October) may well be adequate if your winter bedding consists of regularly changed shavings or a similar bedding that does not offer an environment that is friendly to mites infestations.

A new study has shown that horses with tapeworm are up to 8 times more likely to suffer from colic. The timing of the tapeworm control doses is based on the life cycle of the worms. If the horse overwinters on grass and you want to worm twice then double dose with a Pyrantel Embonate product in March and September. If the horse is stabled over winter, then double dose with a Pyrantel Embonate product in June and October or near to those months to fit in with your grazing season worming programme


Develop an effective worming programme on an annual basis (not each time you worm your horse). Select one of the 3 distinct chemical groups, which are

AVERMECTIN lvermectin and Moxidectin


BENZIMIDAZOLES Febendazole, Mebendazole, Oxibendazole

Use your selected group during a 12-month period with particular emphasis to rotation during the grazing season. Change your selected group annually to a different chemical group so that your stock does not build up a resistance to wormer use. Although most of the leading brands of horse wormers are effective against a broad spectrum of worms there are times when you will need to worm tactically. Which ever chemical group you choose to use on an annual basis you will still need to dose tactically at certain times of the year for effective Inhibited Small redworm, Encysted Small Redworm, Tapeworm and Bot control.

Tim Mackintosh()