DIY Worm Egg Count

LostCovey

This is a simple way to do your own worm egg counts, and where to get cheap gear to do it.

You can find a more detailed explanation with photos here that will be very helpful if you decide to try this
http://www.rvc.ac.uk/review/parasitology/EggCount/Step7.htm


You need
- to be able to use a simple microscope (very easy, they come with basic instructions)
- to have reasonable manual dexterity - if you can wire a plug, you can do this
- to know what worm eggs look like
the most common ones (roundworms - strongyle eggs) look like this http://www.rvc.ac.uk/review/parasitology/EggCount/Exam2.htm
the others look like this http://www.rvc.ac.uk/review/parasitology/RuminantEggs/Common.htm



The Shopping List

1. Two beakers and some test tubes
Small plastic containers like a plastic jamjar, or and old cup will do fine as beakers. Anything that will hold a couple of hundred ml of water, that you can wash and is hard to break
Universal containers (any chemist will have these) are fine as test tubes) at €1 or so each

2. A cheap tea strainer (any big supermarket has these), or http://cgi.ebay.ie/Tea-Strainer-plastic-nylon-mesh-7cm-diameter-/150639096103?pt=UK_Home_Garden_Food_SM&hash=item2312ca3127#ht_659wt_907

3. Measuring cylinder (plastic again, so it won't break e.g. http://cgi.ebay.ie/50ml-Plastic-Graduated-Measuring-Cylinder-Laboratory-/380212215052?pt=UK_BOI_Medical_Lab_Equipment_Lab_Supplies_ET&hash=item588669fd0c#ht_1033wt_907

4. Stirring device (spoon)

5. Pasteur pipettes (eye dropper type of device. A syringe will do but better to buy cheap plastic ones like these http://http://cgi.ebay.ie/20pcs-MINI-0-5ml-New-Graduated-plastic-Pasteur-Pipette-/270806515771?pt=LH_DefaultDomain_0&hash=item3f0d53803b#ht_2453wt_1141)

6. Saturated salt solution (heat a litter or two of water, keep adding salt till no more will dissolve, the clear fluid is saturated salt solution. Let it cool and put it in a clean bottle, along with the salt in the bottom.

7. McMaster counting chamber
Buy the cheapest you can, don't buy the good ones (eg Whitlock brand) these are too dear for ordinary use and they are glass and they are fragile. Buy a cheap plastic one. They are fine, unlike the expensive glass ones, they eventually do get stained, and then you buy another one.
See http://cgi.ebay.ie/Mcmaster-parasite-egg-counting-chamber-single-unit-/130565901476?pt=LH_DefaultDomain_2&hash=item1e66558ca4#ht_500wt_1156)

8. Compound microscope
• Cheap and cheerful, you only need a 10X objective lens, so one from LIDL, or the upper end of the economy ones on eBay is fine eg http://cgi.ebay.ie/ULTRA-400M-Zenith-ULTRA400M-Advanced-Student-Microscope-/150373710628?pt=UK_Collectables_Scientific_MJ&hash=item2302f8bb24#ht_500wt_922

The Recipe:

Mix the faecal sample in the ratio of 1 part faeces in 15 parts water with the saturated salt in the graduated cylinder. This is very important you need to mix it very well, and break up any lumps, not so easy with dryish sheep droppings.
Depending on the size of your cylinder, you could put in 15 ml of saturated salt, then keep adding faeces till you get the mix to 16 ml, or 30 ml sat salt, keep adding faeces, till the mix is 32 ml, you get the picture
I use a 50 ml cylinder with 45 ml saturated salt, and add faeces till I get 48 mls of mix.

Mix it really well and fast, and while its still swirling, strain it through the tea strainer into the beaker.

You now have a 1in 15 mix of faeces and saturated salt, with coarse bits of grass and vegetation filtered out

Take your McMaster slide, rinse it under the tap and shake all the water out (you want it wetted but with no big droplets in it).

Put the McMaster slide on a sheet of newspaper or a sheet of paper towel on a flat surface beside the microscope (which you have plugged in and switched on, and focused it on the lines of the empty slide)

Take the plastic Pasteur pipette, mix it fast again, and while its still swirling suck up a ml or so and quickly fill the two chambers.

This is tricky, and you will do it a few times before you get the hang of filling the chambers evenly with no bubbles.

Make sure you mix well before every step, and don't hang about. Worm eggs float in saturated salt, and you want to have an evenly mixed sample.

When you have filled the chambers, put it on the microscope, leave it for about 10 mins for the eggs to float up and count all the eggs inside the ruled square in one chamber (and multiply this by 100) or in both chambers (and multiply this by 50).

This is the count of eggs per gram.

Prof LostCovey

Cran

Thanks Covey much appreciated, mods any chance this could be made a sticky

Feargal as Luimneach

LC, don't forget though that the technique you described will not detect Fluke eggs.

LostCovey

Feargal as Luimneach wrote: »

LC, don't forget though that the technique you described will not detect Fluke eggs.

No Feargal, it doesn't detect fluke eggs which are too heavy to float ina saturated salt solution, there is a much simpler technique with less equipment needed for liver/rumen fluke.

Just to explain the context, there was a request for a simple worm egg count method for sheep so people could assess the efficacy of the wormer they are using rather than guessing that it is or isn't working.

This is all in the context of stopping/delaying the onset of wormer resistance.

Do you do your own fluke and worm counts?

LostCovey

flatout11

Feargal as Luimneach wrote: »

LC, don't forget though that the technique you described will not detect Fluke eggs.

technically you are correct but i think the procudure can be modified to detect them but fluke its not really an big issue in mid season lambs

LostCovey

flatout11 wrote: »

technically you are correct but i think the procudure can be modified to detect them but fluke its not really an big issue in mid season lambs

I completely agree flatout11, and even if it was, there would be no eggs to find for three months after they pick up the fluke.

You can use zinc sulphate instead of the salt in the recipe above which will float them, but its not always easy to get, and it makes the flukeeggs get very distorted, so most people do a sedimentation to detect fluke eggs.

LC

Feargal as Luimneach

LostCovey wrote: »

Do you do your own fluke and worm counts?

LostCovey

No, but with ever tighter margins I think I should invest in the set-up. The regional labs are very expensive. It's an easy set-up as you described. Did plenty of faecal egg counts in college.

LostCovey

Feargal as Luimneach wrote: »

No, but with ever tighter margins I think I should invest in the set-up. The regional labs are very expensive. It's an easy set-up as you described. Did plenty of faecal egg counts in college.

Yeah the savings are nice, but I think there is also a feeling that you are beating the system anytime you do any DIY - there is a kick out of doing something with your hands that someone wants to charge you for.

eBay makes all things possible.

LC

Bizzum

LostCovey wrote: »

- there is a kick out of doing something with your hands that someone wants to charge you for.

The mind boggles.................At least mine does!:D

LostCovey

Bizzum wrote: »

The mind boggles.................At least mine does!:D

It's too late to 'rise' to that.........

5live

Thanks LC. And +1 on the sticky;)

munkus

Lads,

Does anyone here carry out this practice? sounds like a great idea and not too expensive to setup either.

For anyone who does, how are you getting on with it, are you successfully identifying the eggs etc.