Fecal Egg Counts for Animals
by Tiffanee Boone
Fecal egg counts may be performed on any livestock species, but they are especially important for goats and sheep. Parasite resistance to dewormers has become a huge problem in goats and sheep. You can learn how to count eggs yourself at our Extension Office.
Farmers use fecal egg counts to determine if their dewormer is still working on their farm. They count eggs in feces from each animal, deworm the animals that need it, and then two weeks later, do another count. If the worm egg load has not decreased by 90%, then the dewormer is starting to lose its effectiveness. Egg counts with less than a 60% reduction indicate severe resistance. In that case, the grower should switch to a different one of the three classes of dewormers. The grower cannot just switch to another brand name of dewormer because it could be in the same class; he or she must look at the class when switching.
When counting, you are checking for barber pole worm in goats and sheep, because it is the parasite that causes most of the problems. Infrequently, the real culprit is other parasites such as liver flukes or coccidia. They require different treatments, so it’s important to first figure out what you are dealing with. You may have some animals on your farm that have problems, but when you check the fecal eggs in the microscope, they may not have a heavy worm load. This is important to find out as you are trouble shooting, because you can eliminate parasites as the cause. The animals instead may have a disease that you will need to treat.
When checking fecal egg counts, you may discover a few animals in your herd that always have high worm loads. This is why keeping good records is really important. At that point, you may decide to cull those animals off your farm. Susceptibility to parasites is moderately heritable, so it’s a good idea to sell those animals instead of breeding them since they can pass on the resistance problem to their kids and lambs.
Several farmers have gotten serious about fecal egg counting. After getting trained, they bought their own microscope and supplies to do their own counts on the farm. If an animal is doing poorly, that is often the first step they take toward troubleshooting the problem. Alternatively, other farmers choose to only run samples once in awhile, so in that case they bring their samples to the Extension office to count the eggs. Yet other farmers take their samples to a local veterinarian to analyze.
Whichever way you decide to go, fecal egg counts can benefit your farming management plan. You can work with your veterinarian on threshold limits, so that you know when deworming is needed. Just a few worm eggs in every sample is normal. Parasites like warm, wet weather, so you may need to do fecal egg counts more frequently during such conditions, but you can check them all year. The supplies that you will need include a microscope that is able to magnify 100 times, a measuring vial or scale, a McMaster slide (preferably with green lines for more visibility), cups, fecasol, a strainer, popsicle sticks, a timer, gloves, and an eye dropper.
If you need help with deworming information or would like to learn how to do your own fecal egg counts, please call Anthony Growe at our office at 910-997-8255, or email him at firstname.lastname@example.org