What IS a worm egg count?
A worm egg count is a microscopic examination
of a faecal sample from an animal or ground in which the various parasites
and larvae (worm eggs) are identified and counted. The result is an estimation
of the number of eggs per gram (epg) of faeces and this leads to an estimation
of the degree of infestation of the animal, group or habitat.
The counting is performed on a measured sample in a specific dilution
which permits the calculation of the epg and the degree of infestation
is developed from the estimated output of faeces from the animals with
respect to the body weight, etc. The epg is a useful indicator of the animal's
Can I do it?
Anyone with the small equipment and a willingness to learn can certainly
What do I need?
You need a graduated microscope slide, a microscope, some small bottles,
salt solution, water, and a developed ability to identify parasite worms
You also need a notebook in which to record the results fro your farm
history. The counts can be a useful guide to the overall health of your
Is it expensive?
No. At $65-$75 for the slide, $200-$600 for a microscope (and you may have
other applications for THAT) and a couple of dollars for the buckets, bottles,
water, salt etc.
How do I know if I've GOT parasites?
The worm egg count is a positive indicator, even if your animals look healthy.
They might be dangerously close to becoming obviously ill.
If your animals LOOK sick, but with few external and obvious reasons,
suspect worms! And start checking.
What sort do I have?
The worm egg count will provide a positive identification that will allow
the correct action. You can target drenches or other treatment with full
knowledge of what you are fighting without wasting money on unnecessary
How do I know if they are a PROBLEM?
The epg indicates how great a problem you may have.
Low numbers are normal.
Very high numbers are serious (your animals should be dead?)
What is Drench Resistance?
Drench Resistance in animals means that the parasites that infest your
animal are resistant to particular drenches. There are many ways of combatting
this including varying the drench, rotating paddocks, etc.
You need to know what parasites infect your animals and whether there
are enough to be of concern. If you suspect drench resistance consult your
local vet or Ag officer. There are tests available which can identify the
drenches to which the parasites infecting YOUR animals are resistant.
What is Worm Resistance?
Some lucky farmers are blessed with animals that seem to not become infected
with parasites as readily as the rest of the group. They appear to be resistant
to parasites. This does not mean that they don't become infected at all,
but given the other factors are the same, these animals are less affected
than others. Project Nemesis has brought together a range of research results
indicating that breeding for worm resistance as part of an overall quality
improvement breeding program is feasible.
Where can I get more information?
Your local vet.
Pharmaceutical companies (Drench suppliers)
CSIRO extension services.
Project Nemesis -
Dept of Agriculture -NSW, VIC, WA,
Parasites: Reference books.
Can I do a Course?
Dept of Ag field days. These have been provided in each state for many
years in specific areas. All have been based around the CSIRO developed
technique at the McMaster Laboratories using Whitlock Counting slides.
TAFE- In NSW, Goulburn, North Sydney, Sydney, using Whitlock Counting
UNIVERSITY- Veterinary Science courses around Australia teach the technique
using Whitlock counting slides. Few seem to provide practical short courses.
Where did these slides come from?
The slides were invented in Australia as part of a CSIRO developed research
method to obtain faster and more reliable information on drenching and
The inventor was Harold Whitlock and the Technique was first published
by Gordon and Whitlock in the J.CSIR in 1939.
Who else uses them?
All major laboratories in Australia. Most vets who are providing worm
egg counts directly. The drug companies' research stations in Australia.
UN FAO projects in Pakistan, Indonesia, Vietnam, Cambodia, South America,
Africa. CSIRO collaborative projects throughout the Asian countries, including
mainland China. Even a Saudi Arabian Sultan's Racing Camel stable uses
Where can I get them?
JA Whitlock & Co.
Some state distributors have provided these slides for many years including
Crown Scientific (Qld)