When I was in the store yesterday I asked how good the test was for lung worms and fluke in the sheep ,the lady said "stomach worms were a lot easier to detect." 
Can you shed a little light on this -does what she said mean fluke and lungworms may not be detected even if they are present in the animal?
yay something I can help with. Ok here goes.
gut worms (GINs) can be detected using flotation methods. Quite easy to do, and fairly representitive as the eggs are laid in the gut and pass right out.
Fluke are a whole different kettle of fish. Their eggs don't float very well in the standard solution, and can collapse in on themselves because of the salt even if they do float, which makes them hard to identify. General practice is to perform a sedimentation rather than floation when looking for fluke eggs, as far as I understand this isn't done as commonly and so not everyone is set up and experienced with it.
Not only do you need to perform a different test for looking at fluke eggs but the biology of them makes egg count less straight forward than with GINs. Eggs are released from fluke in the bile ducts and pass through to the gall bladder. They can sit there for about 3 weeks before being passed out with faeces, and they don't always come out in a constant flow. This means that the distribution of eggs in the faeces can vary from day to day and from gram viewed to gram viewed. (I always view 3g of faeces to give an eggs per gram back to the farmer, better chance of catching them). To make matters worse the fluke themselves don't lay at a constant rate and so the eggs are entering the gall bladder sporardically and leaving sproradically. The fact that eggs can stay in the gall bladder for up to 3 weeks means that sometimes when you kill fluke with a successful treatment you can get eggs coming through after they have died. Which is why if you're going to look at a post treatment sample you really need to look at a pre treatment sample too so you can compare the two (there should be less eggs in the post treatment).
In all FEC isn't great for looking at fluke, but short of shooting the animal and looking at it's liver it is the best we have at the moment. That's where my PhD comes in, seeing if we can improve the situation. What you can tell from a FEC:
1) you haven't treated your animals and you have fluke eggs = you have fluke
2) you haven't treated your animals and you don't have fluke eggs = you might have fluke (too young to detect or very low numbers)
3) you have treated your animals and there are eggs but you didn't do a FEC pre treatment = you might still have fluke
4) you have treated your animals, did a pre and post Tx FEC and there are no eggs (or you've had a large reduction in eggs) = you probably don't have fluke
5) you have treated your animals, did a pre and post Tx FEC and there are similar or greater numbers of eggs = your treatment didn't work (
does not mean resistanance!)There is a test about now that shows promise for detecting live and dead fluke, and to be better able to detect small numbers of fluke, but we are still validating it. I don't know of anyone offering it commercially yet.
Lungworm I don't know as much about but I do know they need to be cultured, so again a different test to the standard GIN floation FEC. I would assume that is why they mentioned them to you too.
Hope that helps people!
Dans
Topic: Sheep poo! (Read 28348 times)
