Pinworm again....sighs

[Birker2020]

My horse developed pinworm showing effects 5 days after moving yard although unclear how he got it. After three weeks of treatment including a wormer orally and up bottom, steroids to reduce itching injected and orally and scabs where he'd rubbed had healed vet said was clear of it. he went ten days clear of being symptom free and i thought it was all ok. then last saturday he was frantically whirring his tail and clamping down and when i lifted his tail i saw thats mrs pinworm and kindly laid more eggs overnight! so i have more selenium shampoo and pinworm wash and are starting all over again. anyone suffering from this at present with their horse? Intwrested to know what wormer you have been told to use. one up bum was ivermectin as vet said pyrantel no longer working due to worming resistance

 

[Casey76]

Sorry you have this again, I know pin worm is a pernicious b*gger to get rid of. have you tried calling Westgate Labs to see if they have any ideas which may be newer than the vet knows about?

I think I remember reading somewhere that someone was worming weekly (top and bottom) weekly for 2 months before the horse was considered to be clear (but I may be making that up - my memory is like a sieve).

 

[Shay]

It is a complete pain to get rid of. A horse on our yard has it - he never seems to be completely clear. I understand the vet has said - in his case at least - its because of a decreased immune response which means he can't keep the worm burden under control himself as the horses would do naturally. Might it be worth getting bloods done for your boy? I think technically you're supposed to disinfect all walls, fence posts, rugs, brushes etc as well as eggs can live on untreated surfaces for a long time?

 

[Zuzzie]

See my note below which I posted a while ago. I realise you probably know most of this but the general consensus now is that Panacur Guard 5 day wormer is the best one to use. These pinworms are becoming more and more prevalent and vets are only now waking up as to how to deal with them. Hopefully, if we get a really cold winter it will kill of the eggs on the pasture once and for all.

Quote:

The pinworms live in the rear end of the horse. They come out when the horse is resting, normally at night, and lay their eggs around the anus. You might see a sticky substance containing the eggs deposited by them around the anus. The eggs drop off into the bedding and pasture or by being rubbed onto stable walls and fences. Horses carrying these worms will often scratch themselves to the point of making sores which can get infected. But not all horses scratch. They can be a complete nightmare to get rid of and can take up to 18 months to 2 years to eradicate. This is because you need to break the cycle of the horse ingesting the eggs and then breeding again. The eggs can remain viable outside the body for about 6 to 10 weeks.
Ingested eggs hatch in the small intestine releasing the L3 larvae that penetrate into the mucosa. About a week later they molt to L4-larvae that attach to the mucosa of the ventral colon. About 2 months later they complete development to adult worms. Sexual maturity is reached 3-4 months later.

The time between infection and first eggs shed (prepatent period) is 4-6 months, although there are reports suggesting that it may be shorter based on the observation of foals not older than 3.5 months that already carried Oxyuris egg masses in the perianal region.

It appears that normal wormers are ineffective because they are absorbed before they get to the worms in the hindgut. The only success most owners report is using 5 day panacur guard combined with the use of Neem Oil. You can buy organic Neem Oil cheaply on Ebay. You need to paint the Neem Oil on every day, preferable twice, but more importantly at night. This oil prevents the eggs from sticking and also is a powerful insecticide which harms the worms if they touch it. Some people say that it also interferes with the hormones of the worms - not sure about that though. Some owners have also used syringed wormers by inserting them in the anus but some vets say that this does not work.

It is advisable to disinfect the stable, (walls and destroy bedding) and the grooming kit.
Apart from being ugly and creepy they don't actually harm the horse unless, of course, the horse is causing sores from scratching.

Unquote.

Hope this helps. But as you can see they are a s*d to get rid of!

 

[Andalucian]

Need to worm twice, 3 weeks apart, orally and the other end. Life cycle is 3 weeks so you only get live ones with the first wormer, second one gets the residual eggs that hatch after.

If you've done this, and still got them then I'm stumped

 

[Beausmate]

I wormed with ivermectin every ten days, five times in total, plus used neem oil on the anus during the worming period and for ten weeks after. They went for a while, but returned. Five-day Panacur and neem for three months and no sign of anything since spring. I haven't done any disinfecting, or cleared out the stables, but none of mine seemed to be rubbing on anything and they mostly stay out.

Only two definitely had them, the youngster didn't show any signs, but was treated too, just in case. The two that had them were both diagnosed with Cushing's this year, which might have had something to do with it too.

 

[hairycob]

I got an overreaction wash from the vet. Worked then washed with the ivermectin and slathered with Vaseline daily. Worked again 4 weeks later and then again after another 4 weeks. That seemed to do the trick.

 

[samlf]

As others have said it can be difficult to get rid of and you need to worm very regularly initially to catch the emerging worms. I would also add that as well as regular worming (3-4 weeks apart) you should rotate the wormers to try to avoid resistance - the modern wormers (macrocyclic lactones eg ivermerctin) are technically effective against pinworm but tend to be absorbed too early in the gut to actually be effective in practice. I have had success with double dose of pyrantel, benzimadzoles are also effective.

If you observe strict washing, cleaning of anus, application of Vaseline and/or neem oil, and correct worming intervals and still struggle your vet should be able to import a product from USA that is very effective - piperazine.