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Doing a fecal egg count at home - Page 3

post #21 of 26

Heres what I learned about testing for worms.  Let me start by saying that Im not an expert on veterinary parasitology.  Ive been quite interested in parasites in backyard flocks and decided to take this opportunity to learn and share what Ive discovered.   Ive spent a few days delving into the primary literature as well as web sites discussing worming issues.  My aim is to present some of the highlights of what scientists and veterinarians are currently thinking about with quantifying and treating worms.    The methods of identifying and counting worm eggs are generally the same, regardless of the animal sampled.  The worm species one will need to identify will vary depending on the host species examined.

The McMaster technique
The most widely used test for quantifying worms in fecal samples is the McMaster egg counting technique.   The advantage of this test is that you get a relatively reliable count of the number of worm eggs per sample.   It also requires very little equipment, just a standard compound microscope, things to measure and strain the feces, floatation solution and a McMaster slide.  Ive read that you can purchase the equipment for under $200 and as little as $100 if you look around and buy used.  The McMaster slide has two grids etched onto it with the grid covering a particular volume.   You simply measure out a volume of feces and put it into the floatation solution (which can be made from common things found in the home), strain the feces and place a sample onto the slide and wait five minutes for the eggs to float to the top.  You then count the eggs contained within the grids.  By knowing the volume of feces and floatation solution and the counts of the volume on the slide, you can easily calculate eggs per gram (EPG).  This test is good for quantifying the number of eggs in most livestock feces; different species might require different fecal preparation procedures.

Here is an excellent site with a complete tutorial on how to conduct the various egg counting techniques, including the McMasters and images of the egg types for poultry, ruminants and pigs: http://www.rvc.ac.uk/review/Parasitology/EggCount/Principle.htm.  This site provides very specific instructions, an equipment list and also explains how to calculate EPG.

Here is a site that sells home kits for poultry diseases (worms, coccidiosis): http://www.brunelmicroscopes.co.uk/coccidiosis.html and here is another kit, cheaper, but without the microscope: http://www.vetslides.com/EPGfecalkit.html

I
think that just about anyone could learn to count the worm eggs in their own animals; its very much like following a recipe.  Exact, repeatable measurements are a must.  The main limitation would be in your ability to differentiate and identify the worm eggs.  If you look at online pictures of different egg species and dont see obvious differences, you might have to work harder on those skills.   Because youre working with fecal material and potential pathogens, safety measures should be thoroughly researched and employed.

Interestingly, when a group of organisms is tested, usually one or two individuals are shown to be shedding the greatest numbers of parasitic eggs.  Most of the group will be shedding a relatively lower baseline number and are thought to be more parasite resistant.  Once you know which individual animals in your group are shedding the most worm eggs and the species of worm, you can choose an appropriate de-wormer (anthelmintic) and target those individuals, rather than treat the entire group.   The idea is to strategically limit exposure of the worms to de-wormer so that you do not breed resistant worms.

At what EPG count would you decide to worm?
This is a hotly debated issue and can vary by host and worm species as well as the agency or group making the recommendation.  As if it werent complicated enough, certain worms are more active during particular times of year, and therefore, baseline counts can vary with season.  I found various values for sheep, goats and horses, but nothing for poultry.   They actually might be available; I simply have not found them yet.  Im waiting on several papers I yet need to read.  I expect the recommendations to be included in the WAAVP guidelines (described below).

Fecal Egg Count Reduction Test (FECRT)
The FECRT is simply a way to determine if your de-wormer is effective.  You first conduct a quantitative test, such as the McMasters, and THEN de-worm your animals.  After a period of time, typically 10-15 days, the animals are re-tested.  One can then calculate the percentage that the eggs were reduced by the de-worming treatment.  Its a generally accepted standard (albeit seemingly arbitrary) that a 95% reduction or less in eggs following treatment indicates that worms are resistant to the de-wormer (e.g.: http://sheep.osu.edu/2008/06/20/determining-worm-resistance-to-dewormers/).  Again, the 95% value is somewhat controversial; some argue that anything less than 99% indicates resistance to the dewormer (e.g.: http://www.cluthavets.co.nz/sheep-preparation-for-faecal-egg-count-reduction-testing-fecrt.html).  Whatever cut-off value you choose, the FECRT data will tell you if your wormer is effective or if you need to use a different product.  Here are the references to the guidelines of the World Association for the Advancement of Veterinary Parasitology (WAAVP) on how to evaluate the effectiveness of a de-wormer for various livestock species: http://www.waavp.org/node/25.

It
turns out that lots of people do home testing for worms, especially those with goats and sheep, but also those with cattle, horses and swine.   I was surprised at the number of web sites individuals have created describing their own methods for quantifying worms.  This is, in large part, out of necessity.  Unfortunately, worms become resistant to specific de-wormers and once a resistant strain spreads, the consequences can be costly.  Perhaps the most fascinating thing I discovered is that many breeders are using FECRT counts to identify individuals with consistently high or low values and then using that knowledge to inform culling and breeding decisions.  In that way, they are able to increase resistance to worms in their bloodlines.  This may be the single best reason to quantify and monitor worms in backyard poultry flocks.

Here is an excellent synopsis of the issues and description of methods: http://www.scsrpc.org/SCSRPC/Publications/part6.htm This document was produced by the most awesomely named, Southern Consortium for Small Ruminant Parasite Control.  The article deals specifically with goats, but the issues for worm assessment and control are well explained.

Here is a recent review of the scientific research on worming issues in horses: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2751843/ Again, while it deals with horses and not poultry, it describes what can happen when de-worming practices lag behind current veterinary recommendations.
If you are thinking about assessing worms in your own backyard flock, arm yourself with the best current knowledge and do your own research.  Here are some good terms to use in your online searches:  anthelmintic, FECRT, anthelmintic resistance, worm resistance.

As I learn more, I'll update what I'm learning here and on the byc page I'm making on parasitic worms: http://www.backyardchickens.com/web/viewblog.php?id=56638-parasitic-worms  I'm looking forward to hearing what others are doing!


Edited by Gallo del Cielo - 2/4/11 at 7:01pm

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Check out my award winning feed saving treadle feeder

Thinking about raising mealworms?  Here's how I do it

Got poultry ticks?

Tending my cubic meter sunken garden with my eight ladies

Reply
post #22 of 26

May help, may not help, but about 6 years ago I bought a reasonable microscope that had 4 powers and a slide flip..and light.
It also had plastic slides and plastic tweezers, a kid's microscope kits at Toys R Us.
Waite, don't laugh !
I have used it over and over and then had friends coming over asking and wanting smears to be read.
We got glass slides elsewhere..but anyway we used this microscope to look at smears taken from our koi, looking for parasites, flukes and leeches.
I do not have it here to tell you the product name, but it worked great!!
I will surf Toys R Us and see if I can find it.

Check here:
http://www.toysrus.com/search/index.jsp?sr=1&f=Taxonomy%2FTRUS%2F2254197&kw=microscope&origkw=microscope&kwCatId=&pg=2

I think the starter 450X is kind of what I have in storage, love it.
It goes 150, 300, 750 and 900 I think.
At 900 things get pretty strange !


Edited by Chickielady - 2/5/11 at 6:21pm

 French Silver Cuckoo Marans  , Crele  Albertan  project, BBS Jersey Giants, Blue Copper Marans & Bielefelders.

Muscovies & Crested Pekins , & started birds, chicks and hatching eggs for sale.  Member  SPPA, WFF & the AARP gig.gif 

 

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 French Silver Cuckoo Marans  , Crele  Albertan  project, BBS Jersey Giants, Blue Copper Marans & Bielefelders.

Muscovies & Crested Pekins , & started birds, chicks and hatching eggs for sale.  Member  SPPA, WFF & the AARP gig.gif 

 

Anyone can e-mail me at : Spiritwood_Farm@comcast.net~~~~~~   

Reply
post #23 of 26

Sure!  I'm keeping my open for a used microscope, even it was originally from Toys R Us!

Quote:
Originally Posted by Chickielady 

At 900 things get pretty strange !


It's a whole other world.  gig

Check out my award winning feed saving treadle feeder

Thinking about raising mealworms?  Here's how I do it

Got poultry ticks?

Tending my cubic meter sunken garden with my eight ladies

Reply

Check out my award winning feed saving treadle feeder

Thinking about raising mealworms?  Here's how I do it

Got poultry ticks?

Tending my cubic meter sunken garden with my eight ladies

Reply
post #24 of 26

Parasitology...it's great!


Edited by Happycowdog - 2/5/11 at 6:56pm
My kids and my grand-daughter are my life!!  My pets are a cattledog named Jack Quigley, a little funny dog named Penelope, two rescue cats, one EE roo, two light brahmas, three silver laced Wyandottes, and one BC Marans roo and two Marans hens!  Rock on!!!
Reply
My kids and my grand-daughter are my life!!  My pets are a cattledog named Jack Quigley, a little funny dog named Penelope, two rescue cats, one EE roo, two light brahmas, three silver laced Wyandottes, and one BC Marans roo and two Marans hens!  Rock on!!!
Reply
post #25 of 26
Quote:
Originally Posted by scbatz33 

You don't spin a fecal sample. You take the sample, put it in a test tube, add the solution and let it sit for a few minutes. The eggs will float to the top and stick to the glass slide then you put the top piece on and look at it.  Centerfuges are for spinning/seperating blood.

And as for how many is the magic number, If you have one egg, you have worms. I'd medicate at one. But that is me.


I didn't think so either.  Currently I am in school for veterinary technology and right now we are studying parasitology.  Currently we are doing fecals.  They are saying in school that centrifugal flotation requires less time to perform than standard flotation and it is more efficient.  So spinning poop is the way to go!  That is if you load it correctly! sickbyc   In fact, I suspect my brahma has gape worm and I am taking a stool in next week.  I just hope that's the problem and nothing else...

My kids and my grand-daughter are my life!!  My pets are a cattledog named Jack Quigley, a little funny dog named Penelope, two rescue cats, one EE roo, two light brahmas, three silver laced Wyandottes, and one BC Marans roo and two Marans hens!  Rock on!!!
Reply
My kids and my grand-daughter are my life!!  My pets are a cattledog named Jack Quigley, a little funny dog named Penelope, two rescue cats, one EE roo, two light brahmas, three silver laced Wyandottes, and one BC Marans roo and two Marans hens!  Rock on!!!
Reply
post #26 of 26
Thread Starter 

Gallo woot Great job!

Thanks for sharing your research! Those McMasters slides look really helpful.

Happycowdog, Thanks for the info from your course! I can't imagine how to place a test tube with a cover sheet on it inside a styrofoam block in the salad spinner without just simply making a mess. Is there some kind of enclosed plastic vial that we can use inside the salad spinner to collect the eggs? Like this, maybe? http://www.revivalanimal.com/store/p/742-Fecal-Flotation-System.aspx  ... Also, would you post the counts you learn in school, so we know what number of eggs found would call for treatment? That would be really helpful! smile .... (PS ... I am a fan of cow dogs! smile )

Chickielady, good to know a cheaper microscope will do the job! wink

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