Faecal egg counting with the ioLight microscope

Parasite infections are common in cattle, sheep, horses and chickens and other animals and cause both suffering to the animal and loss of revenue for farmers. In the past farmers have often treated parasites with routine use of antimicrobial drugs (antibiotics). However extensive use of antimicrobials is causing antimicrobial resistance to build in parasites, potentially leading to untreatable infections and concerns with the antimicrobials entering the food chain and water supply.

To reduce this problem, farmers, horse owners and vets can test their animals to see if there is an infection that needs treating before giving the drugs, thus reducing unnecessary use of the drugs. This is done by counting parasite eggs in a sample of the animal faeces and then only using drugs if a significant number of disease causing parasite eggs are found.

Faecal egg counting is done by dissolving the faeces is water, adding salt solution to make the eggs float to the top, then putting a small amount of the this into a McMaster counting chamber and using a microscope to count the eggs.

Traditionally this is done be sending faeces samples to a lab and waiting for a day or 2 for the results. But using the ioLight high resolution field microscope this can be done in the field or in the back of a car thus reducing time before treatment can start and avoiding lab fees.

Below are images of parasite eggs taken with the ioLight high res digital microscope using a McMaster chamber. The lines in the images are the counting lines on the McMaster chamber. The chamber has 10 parallel lines, 1mm apart and 10mm long – you count all the eggs between the lines multiply up by a dilution by a factor to get an estimate of the concentration of eggs in the faeces.