These pesky creatures are everywhere and can be frustrating to eliminate. Taking measures to pick up manure in your turnouts, and feed your horses away from manure can help break the life cycle.
Parasite eggs are in the manure. Come spring and warmer temperatures the larvae hatch and your parasite load will increase. Dragging your pasture to make it look pretty will only spread the eggs around. Horses don't eat near their manure, if they have a choice. They are doing what is natural by staying away from the parasites. You can drag your pasture but I prefer to drag when it will be scorching hot and keep the horses off that pasture for 2 weeks. The high temperature will kill the eggs.
I personally feel the best way to manage parasites to check fecal counts. You will know how big your horse's parasite load is and what he is carrying and then you can appropriately deworm. I don't prefer chemical dewormers but they have their place.
We are over deworming our horses and as a result are just building up parasite resistence. I don't feel daily, monthly, or bi-monthly dewormings are needed. I think the chemicals can overload the system and again build parasite resistance. I recommend and prefer to check fecal counts 3 times a year and deworm accordingly if at all.
In boarding situations it may more difficult to get parasite load under control. The large amount of horses and horses coming and going make it hard to handle. Treating with chemicals may be the only way to get rid of parasites. Horses that are not under a heavy work load, stressed, or competing may do very well with holisitic deworming.
My experience with a chemical dewormer: In October 3 years ago I decided it was time to deworm my 4 horses; this was before I did fecal tests. I had 2 kinds of dewormers. Lady and Jack got 'Brand A' and Zoe and Diva got 'Brand B' in the evening after dinner. They all got turned out in the same pasture, fed the same meals, and were brought at the same time. By the following morning, Zoe and Diva could bare walk out of their stalls. They both had an acute case of laminitis! What's to blame? I would venture to say the dewormer. Some may say they had a large parasite die off that caused toxicity in the body. But really, two very healthy mares ages 4 and 12, both had a parasite die off? I think not. The veterinarian that came out said it was unheard of to develop laminitis from a dewormer but all signs pointed right to it. He felt that it was the cause and should be filtered out of the system shortly and they would return to normal. And they were sound after about a week of intensive booting, cold soaks, and hand walking. However, I am now much more cautious about the use of chemical dewormers. Now I support a healthy digestive system for my horse so it doesn't create an environment for parasites to move in and check fecals 3 times a year.
I use natural deworming products around the full moon. The products aren't potent enough for a one time application. I use a natural product for a couple weeks surrounding the full moon. The full moon draws out the parasites from the intestinal lining and the product is more effective at eliminating them.
*This website is for informational use only. It is in no way intended to diagnose, treat, or cure and is not to replace traditional veterinary care. The information described is from my experiences and observations.