WORMING
What should you be
doing about worming
this winter?
Winter’s dormant months mean that many horses won’t
have access to grazing - the main route to a parasite burden. However this
doesn’t mean your worm control programme should also be dormant. The experts at
Pfizer Animal Health discuss what you should consider for winter worm control,
to give your horse the best preparation for the spring and summer ahead.
If you are following a responsible worm control
programme you will have strategically dosed for tapeworm, encysted small
redworm and bots by now. If you haven’t yet treated your horse for these
parasites a practical and cost-effective solution is to give a single dose of
moxidectin and praziquantel.....but what next?
Hopefully you use faecal worm egg counts (FWECs)
during the spring and summer as the basis for your roundworm control programme
along with good management of your pasture.
Control over winter requires a slightly different
approach, not only because many horses spend much less time at grass and so
won’t pick up worms through grazing but also because worms don’t cycle in such
great numbers when the temperature drops. This means that Faecal Worm Egg
Counts are not as useful during the winter because many redworm may not be
completing their lifecycle so fewer eggs may be seen.
In theory low exposure to worms means that there is
less need to give a routine dose unless you are particularly concerned about
the level of worm burden on the pasture being grazed. For horses on winter turn out it is best to
assess the overall risk from the pasture and worm accordingly but stabled
horses treated appropriately in late autumn should require minimal treatment at
least until turnout.
The only complicating factors are tapeworm and in
some cases pinworm as neither are exclusively transmitted during grazing and
are not reliably detected in FWECs. Tapeworm should still be controlled twice
yearly in most cases, although the overall risk can be assessed by a tapeworm
antibody test conducted by your vet. Pinworm, however, won’t show up reliably
in any tests. They lay their eggs around the anus causing itching and are
rubbed off by the horse. They can be transmitted from horse to horse via things
like stables, buckets, hay, bedding and grooming brushes. Prevention includes
good stable management, but treatment will be necessary in the case of an
established burden.
Spring turnout is the most important time to think
about your next steps for worming. The key question is how much exposure has
your horse has had over winter? If you dosed correctly in early winter, minimal
exposure from then on means that treatment prior to turnout may be unnecessary.
However, your strategy may also depend on the grazing you intend to use. Clean
pasture, that hasn’t been grazed for at least six months or has experienced
hard winter frosts, will hopefully pose a lower risk. In this case it may be
sensible to turn out and then use an FWEC to monitor how the worm burden is
developing over the grazing season.
However, turning a horse onto pasture that has been
used heavily (worm eggs can survive on pasture from the previous year) means
you will need to be very conscientious about your worm control programme during
the grazing season. It’s useful to bear in mind that the persistent effect of
some wormers, such as those containing moxidectin, means that once your horse
has been treated it will continue to ‘clean up’ the pasture for a couple of
weeks afterwards. Dosing at turnout, or ideally a few weeks after turnout may
reduce overall pasture worm burden, which could in turn reduce the number of
worming doses your horses need over the summer months.
Ben Gaskell, Pfizer’s veterinary adviser concludes:
“Even though your horse may be less exposed to worm infection over the winter
it pays to stay on the ball with your worm control programme. Better management
at this time of year means that you will be better placed come turnout time and
subsequently may need to worm less during the summer months.”
..............................................................................................................................
Worming Your Horse
“Now is
the time of year to treat your horse for encysted small redworms,”
advise the
experts at Pfizer Animal Health.
These parasites are the most common worms
found in horses today. They can pose a very serious health risk to your horse
and it’s important to make sure that they are treated properly during the
autumn or early winter.
To
encourage owners to dose their horses accurately this season Pfizer is giving
away a free equine weigh tape with every purchase of Equest™ & Equest
Pramox™* - the only wormers in the UK that treat encysted small redworm in a single dose.
Using a weigh tape to work out your horse’s weight helps you to avoid under
dosing, which increases the risk of resistance development.
Small
redworms can grow up to 2.5cm in length and are thin and reddish in colour.
Small redworm eggs are passed in the faeces and then hatch on pasture and
continue to develop into more advanced larval stages before being ingested by
the horse as it grazes.
The larvae burrow deeply into the wall of the gut where
they encyst and may account for up to 90% of the redworm burden in your horse.
Encysted small redworm will not show up in a Faecal Worm Egg Count - even if
your horse has shown a negative or low count it could still be harbouring
several million encysted small redworms.
Encysted
small redworms can remain dormant inside a horse for up to two years, but they
usually ‘wake-up’ in late winter or early spring, developing and emerging from
the gut wall all at the same time.
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. Young horses of less than six years of age are likely
to be at higher risk of the disease but small redworm can cause
life-threatening illness at any time of year and in any age of horse.
“Treating encysted
small redworms successfully in the late autumn or early winter is important to
avoid the risk of larval cyathostominosis"
says Ben Gaskell, Pfizer’s vet
adviser.
“Make sure you choose a product that is licensed to treat encysted
redworms if these are the worms you are targeting and that you give the correct
dose, by weighing your horse beforehand, as this will help preserve the
efficacy of the drug you use.”
When
choosing your wormer this season, ask yourself – does my wormer measure up?
To receive a FREE Weigh Tape valued at £7 that helps
you dose accurately, purchase a tube of Equest or Equest Pramox, and pick up an
accompanying leaflet to apply. Fill in your details and send us the batch and
expiry flap from the pack and we will then send you a FREE Weigh Tape while
stocks last.
For further information speak to your vet, SQP or visit
FREE
Equest weigh tape when you treat for
encysted small redworm this autumn
While stocks last.
Terms and conditions apply.
