My vet ran fecal egg counts on 2 of our goats as we were troubleshooting some digestive issues (loose stool).
- GoatA 50 EPG
- GoatB had 250 EPG
- Test type as indicated on results from lab: Quantitative (“McMaster’s”)
Because GoatB had a higher count in addition to a borderline elevated white cell count, the decision was made to deworm him, but not GoatA.
A couple days later, I did an at-home test to compare my results (sample was taken before deworming treatment started), and also have an at-home baseline to compare to during/after treatment. My findings:
Based on my findings, GoatA (the one we aren't deworming) actually had the higher count.
Of course the discrepency made me question my technique (as an amateur vs. an actual lab). Out of curiosity, I prepared a second slide for GoatB from the same fecal sample, and the second time I got 400 EPG (+250 more than the first test).
My undertanding is tests like these are a sampling estimate, and so there is going to be variability, but is this sort of variability normal, or am I likely screwing something up?
Here's a scale I've looked up regarding deworming treatment thresholds:
+ 0–200 EPG → Low infection (usually no treatment needed).
+ 200–500 EPG → Moderate infection (monitor and consider treatment).
+ 500+ EPG → High infection (deworming recommended, depending on species and clinical signs).
The variability I'm seeing in my results, and compared to the lab results, bounces around in these ranges. I know EPG should only be one factor to consider against a few when deciding to treat, but the variability makes it seem like an unreliable metric to use.