EQUINE WORMING
Nothing is set in stone about what to use and when as you plan your
worm control, as in all walks of life opinions vary and of course
commercial thinking comes into play too. The entire supply chain of
equine wormers is very vigorously regulated and all those in that
supply chain are duty bound to provide the best possible advice and
guidance to you the end user. At
www.wormers-direct.co.uk we have tried to gather all such
opinions and research and use that information to provide guidance
on your worming planning. Hard evidence shows that continuing use of
the same active worming ingredient can lead to resistance so it
seems logical to adopt a rotational approach to product choice.
ROTATIONAL WORMING
We have all noticed a climate change in the UK in the last few years
with wet summers and warm winters just the weather parasites love to
breed and multiply so it is even more important nowadays to take
that expert advice when choosing your wormers as the traditional
natural enemy of those pesky blighters are red hot dry summers and
very cold winters.
When rotating your
worming products of choice make sure you are choosing a different
ingredient not just a different brand. Develop an
effective worming programme on an annual basis using tactical worming
for specific parasites and rotating active ingredients during the
grazing season (not each time you worm
your horse). Select one of the distinct chemical groups, which are:
|
MACROCYCLIC LACTONES |
lvermectin and
Moxidectin |
|
TETRAHYDROPIRIMIDINES |
Pyrantel |
|
BENZIMIDAZOLES |
Fenbendazole,
Mebendazole, Oxibendazole |
Products based solely on
Praziquantel have a role to play in
tapeworm control but must be used in conjunction with products based
on the three main chemical groups.
|
PRAZIQUANTEL
|
Praziquantel |
Combination wormers
are also available containing lvermectin and Praziquantel also
available a combination of Moxidectin and Praziquantel. These
products offer great convenience at times when tapeworm treatment is
required along with routine worming.
Use your
selected group during a 12-18 month period with particular emphasis to
rotation during the grazing season. The
gazing season is basically the summer months and although your
selection of products may well be based on an an annual selection it
is the grazing season when particular attention should be paid to
rotation of the active ingredients. Out side of the grazing season are
the occasions when specific worming products should be used for
tactical equine worming. Change your selected group
annually to a different chemical group so that your stock does not
build up a resistance to wormer use.
There has been evidence of a resistance
building to products in the Benzimidazole group in certain areas so it
is best to take expert advice before relying on products within that
group to control worm burden.
TACTICAL WORMING
Although most of
the leading brands of horse wormers are effective against adult
redworms (take expert advice before relying on Benzimidazoles, ascertain that
your horse is infected with worms that are susceptible to it by taking
a dung sample and having an egg count done)
there are times when you will need to worm
tactically to treat for specific worm types at certain times of the
year. Which ever chemical group you choose to use on an annual
basis you will still need to dose tactically to control encysted
small redworm, tapeworm and bots.
Treat for
Encysted Small Redworm Larvae during the winter months with Equest or
Panacur 5 Day Equine Guard
Treat for Bots during the winter months with Equest, Equest Pramox, Eqvalan,
Eraquell, Vectin, Eqvalan Duo or Equimax
Treat for Tapeworm in Spring & Autumn with Strongid P, Pyratape P,
Equimax, Eqvalan Duo, Equest Pramox or Equitape
(EQUITAPE TREATS FOR TAPEWORM ONLY)
Treat for Large and Small Redworm during the grazing period with
Equest, Strongid P, Pyratape P, Eqvalan Duo, Panacur, Telmin, Eqvalan, Eraquell,
Vectin or Equimax. All products can be used year round for Large and
Small Redworm treatment (WITH THE EXCEPTION OF EQUITAPE AND BEARING IN MIND THE ABOVE ADVICE WITH REGARD TO BENZIMIDAZOLES)
as part of a worming plan with specific products being used for
strategic worming when necessary.
HERBAL FORMULATIONS
Herbal worming products
are now available using a specific combination of plants to
repel parasites. These products can be used throughout the
year as the sole wormer in a horse's worming programme or
alternatively substituting part of the conventional worming
programme. There is no scientific data about how effective
these herbal preparations are in combating worm burden so it is
best to take expert advice before relying on herbal products.
HEALTH & CIRCUMSTANCES
Different chemicals work in different ways within the body of the
dosed horse so extra thought needs to be given to such circumstances
of age, general health condition, administration to mares, foals and
stallions and also pasture management. There are many ways in which
pasture management such as poo picking and field use can help in
reducing the use of chemical wormers and so why not tell the experts
about your particular circumstances and let them tailor a plan
specifically for you.
A critical time for parasite control is the early months so take
special care when treating foals ensure you select an ingredient
that is suitable for use on foals and use that at the correct times.
A common mistake when treating horses is under dosing so ascertain
the weight of your horse as accurately as you can either by busing a
weight tape or even better a weigh bridge. Correct dosing is
important, too little and the product will not work efficiently, to
much could lead to resistance. There are brands on the market that
now that treat up to 700kg in a single syringe which gives that
little bit extra to play with when estimating the weight of your
horses and remember we all lie about our weight so if in doubt err
on the generous side.
THE ENVIRONMENT
Don’t forget the environment when selecting your products be
particularly concerned about aquatic life in and around your
pastures. Make sure that NO product enters the water courses and
protect the flora and fauna from spillage and waste. Above all be
careful when you have your dogs about as some products are very
dangerous and can be fatal if ingested by dogs particularly collies.
You must read the instructions
on the packing and keep your self up to date with the latest
thinking.
The above guidelines to an effective worming programme are the
opinions of the author and are not the definitive answer. They are
however a base for an effective procedure that can be modified with
the assistance of your vet or other professional authorised to advise
on animal health. The author hopes that this article will help you to
care for your horse but cannot be held responsible for any errors,
omissions or changes in acceptable procedure.
FENBENDAZOLE BASED WORMERS
By using a 5-day course of a fenbendazole-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. If the
risk is low due to a balanced and tactical worming programme then this
treatment can be limited to a single dose in February.
MOXIDECTIN BASED WORMERS
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 months and 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.
IVERMECTIN BASED WORMERS
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 febendazole 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.
PYRANTEL EMBONATE BASED
WORMERS
The tapeworm needs forage mites as a
host so a double dose twice a year is required to ensure adequate control
of tapeworm 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 you want to
treat for tape worm twice then a double dose
with a Pyrantel Embonate product in March and September are practical
times. In certain circumstances a double dose with a Pyrantel Embonate product
could be done a little later in the year to fit in with your grazing
season worming programme.
PRAZIQUANTEL BASED WORMERS
Products using praziquantel can be a very
effective treatment for tapeworm in a single dose again being most
effective twice a year but those products that contain ivermectin as well praziquantel
can be used all year as they are also an
effective treatment against bots and round worms. Products that contain
only praziquantel as the active ingredient give owners the option of
treating for tape worm without also treating for roundworm thus helping to
reduce the risk of equine anthelmintic resistance building up This should still be as
part of a annually rotated worming scheme with the other distinct chemical
groups but care should be taken with regard to encysted larvae where a
treatment using a 5-day course of a febendazole-based products should be
used or a Moxidectin based
wormer which has an ability to kill encysted developing cyathostome
larvae (small redworm) in a single standard dose.
