Misconceptions
exist about how to use fecal egg counts (FEC). At Horsemen's Laboratory,
helping horse owners understand the most effective way to use FECs is part of
our mission; as such, we're constantly on the lookout for new information and
research we can share with our customers.
Now
that fecal egg counts are being recommended globally by equine parasitologists
as a way to prevent parasite resistance (resistance of parasites to deworming
medications) in your horse population, identifying optimum methodologies is
likely to become a hot research area. One such study, which looked at how horse
manure storage conditions affected the FECs, was recently conducted in Denmark
and in the U.S.
Performed
at the University of Copenhagen's Department of Large Animal Science, the study
examined storage temperature, length of storage, and type of container (sealed
vs. open); the study was also carried out at a U.S. location in Athens,
Georgia. The study extract is available free of charge on PubMed's website:
Read the study extract here.
The results
in a nutshell: Refrigerated samples showed no decline in egg counts so it's
considered an ideal storage method, however samples that were frozen or
incubated (heated) showed significant declines in count numbers. Length of time
also had an effect, with egg counts diminishing beyond 12-24 hours after
collection. Also interesting is that there were some differences between the
results in the two locations, which researchers attributed to differences in
barn temps.
For
research purposes this study does shed light on the ideal methods for handling
stool samples, however in practical situations we're not usually talking about
ideals. Our process at H-Lab accounts for sample changes during shipping, since
we use the 'Modified McMaster Technique' that allows us to count as eggs any
strongyle largae that hatch during shipping. It's unclear from the study
results whether the research process allowed for the counting of larvae.
What this
means for you, as a concerned horse owner and Horsemen's Lab client, is that
the way your horse's manure is collected and shipped is a factor in the success
of the process. But, there are things you can do; Horsemen's Laboratory has
been processing stool samples sent through the mail for over 19 years, and
we've found taking the following steps will help ensure your sample arrives in
the best condition for examination:
-
Collect
and ship your horse's manure early in the day on a Monday or Tuesday, when it's
less likely to sit in temperature extremes during the shipping process. The
U.S. Post Office recommends the same strategy for perishable goods during the
busy holiday season.
-
Be
sure you're closing the collection container securely. While the Danish study
showed no reduction in egg counts for open-air storage, the U.S. study showed a
decline for open-air storage after 12 hours. Until we know more, seal your
collection kit as soon as you've collected the manure sample.
-
Mail
your sample right away; don't let it sit around the barn for days or weeks. A
fresh sample will yield the best results.
Using these
collection and shipping guidelines can assist in developing an ideal
surveillance program for parasites in your horses, and having the most
efficient detection of anthelmintic resistance in your herd. Parasite
resistance is thought to be forever; this is a case where prevention really is
the best medicine.
Coming
next month: We'll
have an article by Martin K. Nielsen, DVM, PhD, and
assistant professor in the Department of Large Animal Sciences, Faculty of Life
Sciences, at Denmark's University of Copenhagen.
One
of the researching veterinarians for the sample collection and storage study, Dr. Nielsen's also spoken on the topic of equine parasite resistance and was a visiting
scientist at the University of Kentucky's Maxwell H. Gluck Equine Research
Center. We're pleased Dr. Nielsen has agreed to share his knowledge with our
H-Lab clients and friends, so we can continue helping you develop the best worm
control program for your horses.
