Last year, I started a new approach to deworming my horses. I began to base my decisions on fecal tests for deworming versus just putting my horses on a schedule w/o regard to whether they needed it.
This spring's test was amazing to me. Zarah's test was negative - meaning she has too few to justify a count. Rain and Gemini have traces of strongyles, but such a minimal amount that deworming is not warranted. Cowboy has even less than Gem and Rain. Nina has slightly more and could be dewormed, but she'd be fine w/o it. Tina has more and I will deworm her and recheck her to ensure it was effective. Rio has a very, very high count - highest I've seen. That could explain his coarse looking coat and bloated belly.
What's even more amazing is I have now gone 1.5 years w/o administering dewormers to my 3 horses. This is a controversial subject among horse owners and I'm really comfortable with how I'm doing things now. Note: a fecal test does not detect tapeworms. I may administer a dewormer to ensure tapes are not an issue, however in Colorado tapeworm is not prevalent (our arid climate gets the credit, I'm sure).