[Womble]

So now we've been keeping sheep for a couple of years, I'm updating our flock health plan. The original provided by our vet said we should do pooled FECs (testing poo samples for worm eggs) for both lambs and ewes in June, July August and September, and worm only if the results were high. The trouble with this was that they charged £12 for each test, so we should have been spending nearly £100 a year on testing; more than if we'd just wormed them four times a year regardless!

We've changed vet now to one that only charges £5 per sample, which is much better value. I'm keen to hear what other people do though. For example, how often do you have FECs done, and are they pre or post worming? Also do you still worm routinely, or is it now only after a high FEC result?

Secondly, what's your control strategy for Nematodirus?  The NADIS forecast is a great help in knowing when problems might occur, but I'm still unsure what I should be doing in response to that, and when! 

As always, thanks in advance folks!

[Tim W]

Control strategy for nemo---lamb late to avoid the rise is my first move. Then I watch closely for the sign of poor doers, dirty bums, lack lustre coat etc. This year I have dosed 1 flock for nemo (200 out of 1000 lambs)

If you want to save on FEC costs then get a cheap microscope ...the whole set up will cost about £100 and the process will take you 10 mins each time (once you get the idea)

I FEC ewes about a month after lambing to see what is going on , lambs get dome every 2 weeks from about 6 weeks onwards
This may sound a bit over the top but I then have a nice graph of worm burdens that shows me what the trend is , I can then predict in other years where & when my trouble spots may be

If you want to learn how to DIY FEC then I will be happy to show you (might be a bit of a long trip though!)

[clydesdaleclopper]

I would love to learn to do it myself as my vets are really expensive on FECs. Maybe we need SAC to offer a how to FEC course for smallholders.

[Womble]

Thanks both, and thanks for the offer Tim!

I actually have access to a decent microscope at the moment (as well as a fairly serious scanning electron microscope come to think of it!  ). So if I buy the slides, I could give it a go on the cheap without risking very much.

A course is a great idea CC. [member=24086]CarolineR[/member] - one to add to your list?  I'd definitely come

Edit: Just had a call from the vet. The ewe sample was clear, and the lamb sample showed low counts of nematodirus. They've recommended a repeat sample in three weeks time for both ewes and lambs.

So.... say eight tests a year at £5 each = £40. That means a microscope would potentially pay for itself in just over two years. It would also give lots of flexibility on when we test, and give us the ability to check individual animals too, as well as the poultry.  I'm definitely going to have to find out some more!

[CarolineR]

Can definitely add it to the list of requests there!
Just a warning though - Please always remember that Nematodirus battus can cause very severe disease and lamb deaths BEFORE Nematodirus eggs appear in the faeces (this is called the "pre patent period" and refers to the time before worms are mature adults) i.e. like with fluke, disease can be caused by "baby Nematodirus worms" which do not produce any eggs, as well as "adult Nematodirus worms" which do produce eggs.

So a zero Nematodirus egg count, or a low Nematodirus egg count - does NOT rule out Nematodirus as a cause of scouring and death in lambs unfortunately. In the early period, i.e. up to two weeks after a big Nematodirus hatch, if you lose a lamb, sometimes the only way to diagnose it is by postmortem examination. The SCOPS map is brilliant, but the "hatch" in your area does actually vary a bit from the map depending on your holding's elevation (how many hundred metres you are above sea level), aspect (north or south facing), environment etc.
This is all not really the case with a bunch of the other worms, so you do need to know all about your worms before you can successfully interpret your egg counts, rather than just being able to "spot the eggs" which is the easy bit. I already have some more "know your worms" and "know your wormers" courses planned (details in the next month or so about dates) for online stuff, also I will be speaking on worming at the Ryeland Sheep Society meeting on 24th July if anyone is around for that!

Plus, worth noting that if you have Nematodirus but don't act immediately (but do still act quickly enough to avoid lamb deaths) you can sometimes be left with a couple of lambs that have residual kidney damage and die a couple of weeks later even though you've got rid of the Nematodirus with worming treatment after a short delay.

So, while I'd say I have no objection to anyone who wanted to learn to do their own worm egg counts, I would also emphasise the fact that doing a particular diagnostic test properly, and interpreting your own results properly, is something that definitely takes a bit of learning to do - not just learning to recognise the eggs, which is fairly easy and does not take as long, but learning how to sample properly and also what all the different worms do and when, and so what your counts actually mean, otherwise you are just going to get a fraction of the benefit that you would get from a proper lab test anyway. I guess that's probably why a lot of places charge a certain amount - quite often you are paying for the hours of training and learning that has gone in, as well as the simple half hour of processing, counting etc that is all that people tend to think about. I'll shut up now, I could happily talk about this stuff for hours 
Hope this info helps!

[CarolineR]

PS for what it's worth, you might not need to be checking your ewes that often. I don't have all the details, and I'm certainly not disagreeing with another vet on a small amount of info as they will have had more to consider than I do, but SCOPS guidelines on worming  or worm checking of ewes indicate that you *might* not need to be doing them that often so you could always discuss that as a possibility. 
There's a brilliant manual on the SCOPS (Sustainable Control of Parasites in Sheep) website if you are interested - www.scops.org.uk, including the actual manual that vets use as well as the info for farmers and smallholders. SCOPS are the go-to experts for info on sheep worms if you are into that kind of thing.
No really, I'll shut up now     Just a parasitology nerd....

[Marches Farmer]

I think avoiding the wormy pasture in the first place is a key factor.  If you can switch the turnout field between three different fields in each successive year, and always keep wormed sheep in the same field for 24-48 hours after worming or, even better, give them a hayrack on hardstanding, so any resistant worms don't breed with non-resistant worms already in the field, you've gone a long way to improving the outlook for flock health.  Putting weaned lambs on aftermath grazing from a hay or haylage crop is another way of keeping worm numbers down.

[Dans]

Jumping in on this.

I've done worm egg counts in the past but I've been in the lab with access to all the equipment. How do you do them low tech? Microscope obviously needed but do you still spin them down?

Dans

[Womble]

Great info, thanks!

Caroline - I'm aware that nematodirus are a bit different from other worms, which is why I asked the question. I'm still confused because when I said "I have some lambs scouring - can I have some white wormer please, in case it's Nematodirus", the vet's response was "submit an FEC first, as you may not need to", even though as you say, FECs aren't a reliable indicator of early nematodirus infection  . I'm going to see them soon to agree a new flock management plan, so I'll ask in more detail then. In the meantime, please feel free to bang on about parasites - it's actually really interesting!!

About the "switch the turnout field" idea, my understanding is that lambs won't start picking up worm eggs until they start eating decent amounts of grass (so say over one month old?). Does that mean that this really means "use a different field for the lambs each year throughout June and July"?

always keep wormed sheep in the same field for 24-48 hours after worming or, even better, give them a hayrack on hardstanding, so any resistant worms don't breed with non-resistant worms already in the field

Keeping wormed sheep in the same field for a while after worming makes good sense, so they can pick up some 'new' worms to mix with the resistant ones they're still carrying, thus ensuring the resistant worms still have 'competition' from non-resistant worms to keep their numbers down.

I don't understand what's behind the hardstanding idea though?  If you do that, won't the sheep shed their last non-resistant worm eggs on the hardstanding, not pick up new ones, and then go into the new (clean) field carrying only resistant worms (i.e. the ones the wormer didn't kill)? I'd have thought that would increase the prevalence of resistant worms, not reduce it? Help!! 

Edit:  Dans - No, in the DIY method you don't spin them down, you mix them up in a solution with a high SG, which makes them float up. You then draw the worm eggs off the top of the solution and look at them under the microscope. One method is described here, though I'm really not sure it's necessary to go to those lengths to obtain a sample! 

[Dans]

Thanks that sounds simpler.  Is there a guide out there?

That sounds a bit odd from your vet. I'd certainly get clarification.

I was always taught out them back o to the dirty pasture after worming. It dilutes the population of any resistant worms inside them.

I haven't heard the hardstanding advice before though. The only way I can see that helping is if you were doing a quarantine treatment. Treating with zolvix to five them a good clean out. Then you keep them in until they have shed all eggs and turn them out onto truly clean pasture (not been grazed in a good while).

Dans

[Dans]

No really, I'll shut up now     Just a parasitology nerd....

Yay  from another parasitology nerd

Dans

[Womble]

There's a brilliant manual on the SCOPS (Sustainable Control of Parasites in Sheep) website if you are interested

Wow, indeed there is! That's brilliant - I just never clicked on that heading before, because I'm not a vet!

Re FECs, I do appreciate that the cost is in the knowledge, rather than the ten minutes it takes. However, I do still fancy having a go myself (sorry, scientific background - can't resist it!), even if I get the vet to double-check for the most important samples.

The cheapest way to do it seems to be a 100X USB microscope (£20 to £100 depending on quality, though of course  the cheap ones probably aren't that brilliant), plus a mechanical stage for moving the slide precisely (£20), plus the solutions and McMaster slides (£25 for plastic ones). So it looks as though it *can* be done for £100 at a push. (A standard optical microscope might be better in some ways, but I'd prefer a USB microscope because it would enable me to take screen captures to torment TimW with, to get him to confirm what I'm seeing  ). I'm still thinking though, and keen to hear other ideas!