Worming worries

Worming Worries

Parasite control is obviously a vital part of the dedicated horse owner’s care programme.
Domestic horses, limited by the hedges and fences surrounding their fields and paddocks, are
forced to eat grass from their confined area. This sets up a constant re-infestation by worm-
larvae. If not controlled, this re-infestation will build, resulting in horse-sick pasture and
unhealthy, worm-ridden horses. As parasites, worms thrive at the expense of your horse.
Damage can include digestive problems, loss of condition, gut damage, colic from a rupture
or blockage, diarrhoea and weight loss. Losing a horse from colic caused by worms is a real
danger and internal worm damage is irreparable.

Yard Worm Policy

Any equine newcomer to a yard should be wormed on arrival and stabled for at least 48
hours. This ensures all the worms carried by the horse will be destroyed and will therefore be
unable to lay eggs when the horse is turned out. It is imperative that horse owners at
communal livery yards keep to the same worming programme, alternating wormers with
different chemicals in an effort at attacking and reducing the worm burden as possible.

Know Your Worms

• Redworms – the most common worms. Large redworms, ‘Strongylus vulgaris’ and ‘Strongylus edentatus’ and small redworms, ‘Cyathostomes’. The life cycle of the small redworms makes them very dangerous. Treat for ‘Cyathostomes’ in late autumn and again in late Spring. Dose with Fenbendazole for five days in late October/early November to treat encysted larvae. • Ascarids – large round worms can reach 30 cm at maturity. Treat with Ivermectin pr • Lungworm – ‘Dictyocalus arnfeldi’, causes coughing. Treat with an Ivermectin • Tapeworm – ‘Anopolocephala perfoliata’, is thought to be responsible for up to 20% of surgical colic. Pyrantel and Pyratape P need to be given at double the normal dose – in June and/or September. • Bots – are larvae of the bot fly and live off food in the horse’s stomach. Eggs are laid in the summer, usually on the front legs of horses at grass – the tiny yellow eggs are then licked off by the horse. Migration is through the internal organs to the stomach and disorders such as digestive upsets, colic and inflammation can be the result. Use an Ivermectin wormer in December after frosts have killed the flies and the larvae have reached the stomach. Worming Programme

It is recommended that horses have a set worming programme for a year, using a routine
wormer which is in one chemical group, substituting it the next year for one of a different
chemical. In the third year, yet another chemical group should be selected, before returning to
the original group. This has the effect of catching the worms out.
Routine and Specific Wormers

• Routine Wormers – a product planned for general worming throughout the year – a broad spectrum wormer which will kill most worms whose life cycle is six to eight weeks. • Specific wormers – or specific higher doses of a wormer, are used in place of the routine wormer at fixed times of the year. They are required to control key worms, namely tapeworm, bots and encysted small redworm larvae. If your horse over winters on grass, dose for tapeworm in June and September. If your horse is stabled over the winter, worm in July and October. The three chemical groups in which horse wormers fall are:

When to worm?

Worming timetables are based on the life cycles of worms. Worming every 6 to 8 weeks over
the winter months will affect the small redworm. During Summer an interval of 4 to 6 weeks is
recommended.

Finally

Worming requirements may vary per Region or country. Always consult your vet first before
engaging into a worming programme.
Friesians4all Europe – Buyer Information
Postbus 105 – NL-9560 AC Ter Apel (The Netherlands)
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Source: http://www.friesians4all.net/Worming.pdf