how high?? if very high say over 800epg i would do a five day panacur guard, and follow up in 14 days with equest pramox, so you don't run the risk of a blockage caused by worms dying en-masse...need anymore info just pm me!
trouble with pancur is fenbandezole resistance though... depends on what are your in though... some places you may aswell just pour your money down the drain!
I would ask your vet, But worm counts r good iv bin doing them for about the last 6 months cause if their is no worms in your horse i find it pointless pumping chemicals in to there system on the off chance. good luck!!!