Lara,
I wish I had studied 'wormology'! If your horses are on a drylot they are
not reinfecting themselves on worm larva on the grass. If you've done
ivermectin on all three at the same time and you pick up all the manure in
the lot everyday, I dont see why you'd need to worm so often. I read many
years ago that Cornell did a study on dormant pastures - 40 years dormant -
and they still found worm larva. So that says freezing and heat doesn't
kill all of them. Your hay fields should not be grazed. The hay I buy is
"clean" meaning no animals allowed to graze the fields. If we all just use
ivermectin, eventually the horses will become resistant to that too. I hope
Amberlee or Dr. K respond to this - And you need to talk to Amberlee
about your pregnant mare!!
Mandy and Asher in VA
I use CA Trace - its great - contact Sally Hugg at barefoot@...