Resistance to deworming medications is a growing problem. With no new drugs on the horizon, preserving the efficacy of the available products is critical. Parasite control based on fecal egg counts rather than a continuous rotational deworming protocol can be effective for preventing infestations and avoiding resistance.
Basing treatment on the results of fecal testing can be costly in large herds. However, the supplies are readily available and with basic training, livestock owners can learn to run their own.
Emaly Leak owns Autumn Hill Llamas and Fiber in Duanesburg, New York, and has been running her own fecal egg counts since she was 15. She teaches others to do the same and says goat owners can experience the same benefits she has.
â€śOne of the biggest misconceptions is that it takes a veterinary-related degree,â€ť she said. â€śYou do need to follow the protocol with a good amount of attention to detail, and it can be tedious to count potentially hundreds of eggs, but it isnâ€™t hard.â€ť
DIY fecal egg testing can reduce costs compared to sending samples to a veterinarian or university. And it gives you the ability to test whenever needed, like weekends when labs are closed.
Although Leak performs most of her own, she sends samples out to be tested to make sure what she is seeing is accurate.
â€śItâ€™s a good checks and balance,â€ť she said.
Leak uses the Modified Wisconsin Sugar Flotation Method to evaluate fecal samples, which was developed by the University of Wisconsin’s Parasitology Laboratory. This method uses a sugar- or salt-saturated solution, which causes the eggs to float to the top of the sample.
She runs fecal egg counts on her small herd of three to four times a year. For larger herds, experts recommend testing 10 percent of the herd. She also tests any new animal within two weeks of arrival or after a return from shows.
â€śSpring is often an important time to test as the animals are going back out on the pasture where contamination is happening,â€ť she said. â€śAnd females are often delivering their young, which makes them more susceptible to parasites.â€ť
Equipment for Conducing Fecal Egg Counts
Leak says retailers like Amazon and livestock supply companies carry the items needed to perform on-farm fecal testing. Supplies include:
- microscope (with a movable stage if possible)
- test tubes that will fit the centrifuge
- glass slides
- glass cover slips
- popsicle sticks
- paper/plastic cups
- tea strainer
- gloves (latex, rubber, vinyl, etc.)
- plastic baggies or small Tupperware containers
- float solution (saturated sugar solution in water)
- small scale (postage scale)
A Step-by-Step Guide
- Collect fresh samples.
- Weigh 3 grams from each sample and place in a plastic baggie or Tupperware container.
- Mix sample with float solution (volume will depend on the size of the test tube used). Stir to break up the sample.
- Strain the mixture, add the liquid to the test tube and discard the remaining solids. Add additional float solution to the tubes if necessary, to give them all an equal volume. Clean the strainer well between samples.
- Centrifuge the tubes for 10-15 minutes.
- Add more float solution to fill the entire tube leaving only a slight bubble on top.
- Add a glass cover slip to the top of the test tube. The liquid should touch the cover slip but not spill over.
- Let the samples sit for at least 10 minutes and up to four hours so the eggs float to the top and attach to the cover slip.
- Remove the cover slip by pulling straight up and place it on a glass slide.
- Examine the slide for parasite eggs. Divide the number counted by three to determine the eggs per gram (EPG).
Parasite prevention and management does not equate to fecal samples with zero EPG. That is the biggest change in thinking as the industry has moved away from rotational deworming to an approach based on fecal egg counts.
â€śItâ€™s important to retain a population of parasites in your herd that are still susceptible to medication,â€ť Leak said. â€śYouâ€™re never going to have no parasites in an animal.â€ť
Tips for Getting Started
Leak says it’s best to learn the process from someone else and recommends finding a mentor to teach the process. Classes are also often available, though these may be harder to find amid the coronavirus pandemic.
â€śA lot of people are happy to teach one on one,â€ť she said. â€śIt is hard to learn without seeing it in person, and it is very helpful to have someone to answer questions once you get started on your own.â€ť
Finding a good visual resource for identifying parasite eggs and keeping good records of your testing and results is also important, Leak emphasized.