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Time to Worm? Think worm count first!

How to plan a targeted worm control programme based on tests.

It’s the time of year for planning our horse’s parasite control, putting in place measures to ensure their wellbeing is covered for the year ahead with no unwelcome passengers. This no longer means developing a regular chemical programme – The British Veterinary Association and other parasitology experts are asking horse owners to ‘think twice before using wormers’ and advising horse owners to move to test based programmes, targeting wormers where necessary.

Resistance to wormers

Horse worms are evolving to become resistant to some worming drugs, especially those which have been around for a long time. This means that you can no longer rely on keeping your horse worm free purely by giving him wormers.

It’s much better to know what is going on and target the wormers at the wormy horses and at specific seasonal problems like encysted redworms, bots and pinworm. Using wormers sparingly should also mean that they stay effective for those times when our horses really need them.

Using worm counts and tests

Whether you have a single horse kept on an individual turnout or run a busy yard with mixed turnout a targeted approach can work for you.

Redworm, roundworm and tapeworm are the horse worms that pose the biggest pathological threats to equines and the parasites for which you should test regularly. You may also need to consider bots, lungworm, liver fluke, pinworm and neck threadworm in your programme.

How does a worm test programme work?

A mature, healthy horse can follow a very simple pattern of testing and dosing. A dung sample is taken approximately three times a year to check for the presence of redworm and roundworm and a saliva sample twice a year to test for tapeworm.

If all is well then no need to worm. Complete the year by treating for possible encysted redworm in winter. Foals, youngsters, neglected or older horses will require more attention.

A word about encysted redworm

Encysted stages of redworm are not mature so don’t lay the eggs which are counted in the dung sample. It is important to treat with an effective product in the winter months then rely on worm count results over the next season.

Isn’t it expensive?

The main aim of using a targeted programme is to have a healthier horse with good worm control but one of the side benefits is that it is usually a less expensive option.

When you first start there may be a period when you need to both test and give a wormer if a horse proves to have a parasite problem. Using tests means that the problem is recognised and being dealt with.

About the tests

Horse worms under microscopeWorm egg counts are a reliable test for redworm (except encysted stages) and roundworm. Look for laboratories like Westgate Labs that use the industry standard ‘modified McMaster’ worm egg count method including a centrifuge – far superior to simple strained methods for getting a true picture of your horse’s worm burden. 

Tapeworm burdens can be diagnosed using a saliva test which detects tapeworm-specific antibodies present in the sample. The EquiSal Tapeworm test has been developed to reliably detect tapeworm burdens using a saliva swab that you collect from the horse yourself without the need for a vet. The test is scientifically proven to diagnose tapeworm burdens with high accuracy – it tells you if your horse has a burden and whether you need to worm or not.

Pinworm sellotape tests, lungworm sedimentation tests and liver fluke worm egg count tests are also available.

Test costs vary from £9.50 for a standard worm egg count to £17.95 for a tapeworm test and £5 for a pinworm test. Discounts for multiple horses, commercial rates for yards of 10 or more horses. For more information see 

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