FAECAL EGG COUNTS (FEC)
By Dr Mackie Hobson BSc(Agric),BVSc

1. Procedures and Protocols

How to do

Faecal egg counts (FEC) in Angora goats can be done for a variety of reasons:

1.It can help to decide whether drenching is necessary instead of waiting for clinical signs. Don’t use a FEC alone to make dosing decisions – look at           the all the information available i.e.: FAMACHA, body condition score, diarrhoea, age of goats, dosing history, time of year.

2. To determine the efficacy of a specific dose (anthelmintic).

3. As an aid to selecting goats for roundworm resistance.

What do you need?

weigh in 0.1 gram increments; a digital kitchen scale could be used. 2. Plastic cup 3. Faecal flotation solution. This can be purchased or home-made up by mixing 180g salt to 500ml water 4. Syringe for measuring flotation solution 5. Spoon for mixing 6. 2-chamber McMaster slides. 7. 1 or 2ml syringe, or eye dropper, or transfer pipette for filling slide 8. Compound microscope, 10X objective lenses. A binocular microscope is more comfortable than a monocular scope, but not essential.

Collecting a faecal sample:

1. In a flock of Angora goats mark 5 goats (ear tag) that you can sample each time in order to do a FECRT (Faecal Egg Count Reduction Test) when checking for Anthelmintic resistance on your farm. Remember 30 goats can carry 80% of the worms. One can also sample an individual goat if showing clinical signs of diarrhoea to check for parasites.

2. Using a gloved hand remove a good sized faecal pellet (usually weigh about 1 gram) from each of the 5 goats. Another option is to collect a sample immediately after it has been naturally deposited by the goat. If the goat has diarrhoea then the sample can be kept in the palm of your hand and the glove removed to contain the sample

3. Place the samples in the refrigerator (they can be kept for 3-5 days but the sooner analysed
the better .

Procedure

1. Crush the pellets in the glove or crush and mix in a spoon or pestle and mortar

2. Measure two grams (2g) of mixed faecal pellets into cup on scale or on scale directly.

3. Dispense 28 ml flotation solution into the cup, mix and let soak for approximately 5 minutes

4. Mix again before sucking up with syringe or pipette. Fill both chambers of the McMaster slide using a syringe. If large bubbles are present, empty      the slide and refill.

5. Leave slide for 2-5 minutes to allow parasite eggs to float to the surface.

6. Place McMaster slide onto the microscope stage. Focus the grid lines on the McMaster slide using 10X objective

7. Use the fine adjust knob to focus up and down on the faecal material.

8. Read slides by using the 10X objective. Always start the count at the same point on the McMaster slide (for example, top left). That way, you won’t lose track of whether you have counted the chamber.

Count all eggs inside of the grid areas using the 10X objective (include eggs on the grid line if greater than ½ of egg inside grid) in both chambers.

Count separately. A few examples:

• Strongylid eggs (oval shaped), Roundworms

Total egg count: (chamber 1 + chamber 2) x 50 = eggs per gram (EPG)

This multiplication factor of 50 is specific to the ratio of feces (2 grams) to flotation solution (28 ml) described in this procedure.
Each egg observed represents 50 eggs/gram therefore, this procedure will not detect fewer than 50 eggs/gram, which is equivalent to seeing one roundworm egg on the McMaster slide.

Example:

5 eggs seen in chamber one and 3 eggs seen in chamber two
= (5+3) x 50 = 400 e.p.g.

Interpretation

It must be remembered that a number of factors can influence the number eggs found in a faecal sample. In particular.

The number of eggs depend on:

•  Number of fertile adult worms
•  The amount of faeces being produced by the goat (concentration) and rate of passage through intestine.
•  The goats immune system:

•  Stress
•  Physiological status (pregnancy)
•  Age
•  Nutrition

Decision making:

It is important to know the concepts of refugia, roundworm management, FECRT (faecal egg count reduction test), FAMACHA, body condition score and diarrhoea.

Take into account the impact of age and stress of goats, physiological status, dosing history and the time of year.

As a very general rule 200-500 epg is a moderate level, 500-1000 is a high level of worm eggs.

Different types of worms produce different numbers of eggs a day. Example wireworm 10 000epg, bankrupt worm 200, brown stomach worm 100

Speak to your vet.