Encysted red worm -I dont understand

FairyLights

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Can someone help me out here. If I consistantly get zero or very low worm counts why do I need to keep worming for encysted red worm? As if the horse has a very low burden where are all the encysted coming from? Also tapeworm, why are we told to routinely worm for tapeworm burden when we dont even know if the horse has it? Surely blood tests are the way forward here. Years ago I was told there is only horse tapeworm in certain areas of the uk so worming the whole equine population "just in case" seems wrong . We are consantly told to not routinely worm anymore but to have worm counts done for other types of worm so why is it ok to double dose or 5 day worm "just in case". Siurely this is putting lots of potentially uneccessary chemicals into the horse.
 
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Can someone help me out here. If I consistantly get zero or very low worm counts why do I need to keep worming for encysted red worm? As if the horse has a very low burden where are all the encysted coming from? Also tapeworm, why are we told to routinely worm for tapeworm burden when we dont even know if the horse has it? Surely blood tests are the way forward here. Years ago I was told there is only horse tapeworm in certain areas of the uk so worming the whole equine population "just in case" seems wrong . We are consantly told to not routinely worm anymore but to have worm counts done for other types of worm so why is it ok to double dose or 5 day worm "just in case". Siurely this is putting lots of potentially uneccessary chemicals into the horse.

Hi
Encysted red worm are an immature form of the red worm. Red worm sometimes migrate into the gut wall before they finish their life cycle. If they move into the tissues of the horses they become dormant and can remain in the tissue for an uncertain amount of time. It is not known what triggers the dormant forms of red worm to come back out of the tissues but when they do they can cause quite a bit of damage, partly because of them wriggling back through the tissue and then because the numbers that are released cause an immune reaction and a sort of shock to the horses system. If you use a worming drug that specifies 'encysted red worm' these hibernating stages of the worm are removed before they 'hatch' back into the horses intestines.
A faecal worm count cannot account for the hidden 'encysted red worm' stages because they are hidden. Also encysted stages cannot be tested for via blood, as they are not in the horses main body anti-bodies are not produced by the horse. There is always a possibility that horses can pick up the larval/egg stages of red worm and they then become the hidden stages.
Tapeworm are slightly different, it is very unlikely to see tapeworm eggs or evidence of tapeworms in a faecal worm count test. This is because of the way tapeworm release the sections with eggs in, they are released less often than the eggs produced by the more common strongyle types of worms. Tapeworms are picked up by horses in a type of mite that can be present in hay, forage feeds etc, the mites can even hide in cracks and crevices in stables. So even if you poo pick it is possible for your horse to be infected with tapeworms just because they eat hay etc! Ideally if you can afford to have blood tests, called an ELISA completed, which looks for the anti-bodies in a horses blood (produced because tapeworm are present) at least twice a year then you would only have to worm for tapeworms when there is evidence of them being in your horse.
I totally agree with you about administering chemicals when they may not be necessary but it is usually cheaper to use the chemicals than have blood tests completed. Maybe as horse owners we should start objecting to the costs of these tests!
Hope that all helps.
Ani
 
Very interesting questions.

Redworm can encyst for a long time, over two years so if you have only one or two seasons of good results then you should probably keep up your winter dose as a precaution. It can be Equest, doesn't have to be 5 day guard. However, I agree that if you have had your horse a long time, he didn't have a neglected past, has never had more than a very low count, is kept in a low risk situation, then yes, don't do the winter dose. Keep up your counts and if they remain good then space them out more too.

As to tapeworm, I was talking to a vet about the Elisa test recently and about frequency. There don't seem to be definitive answers but he suggested every two years as being often enough. He also said that for a horse again kept in low risk situation, never had a known tapes problem, then worming once a year, in late autumn is enough.

Now we all know that worm counts are not going to give a definitive answer about tapeworm, unless the eggs are seen, as sometimes happens. However I recently read an interesting article which said that a good time to 'catch' tapeworm eggs in the droppings is just after giving the tapes dose. So if you worm for tapeworm, then test, the tapeworms die and eggs are released into the dung. You then know that your horse is positive for tapeworm and should be wormed regularly for it. I thought I might try this with my own little herd, though of course I hope they don't carry tapes. I've never seen any eggs in their samples which are regularly tested.
Here is the link if you are interested:
http://www.equinescienceupdate.com/articles/fectt.html
 
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