Wormer making horse lethargic?

[Baileysno1]

Has anyone ever had experience of wormers making a horse very lethargic, my friend joined me xc schooling on the bank holiday and was amazed at how dead her mare was, then the following week went to her first ever dressage competition and had the same problems. The only connection was the mare was wormed both times the evening before going out (I'm sorry not sure which brand but obiously something that requires a 7 day follow up if that helps) I vaugley remember being told not to worm before an event as the scouring may upset the horse's digestive system and it may not preform, but wasn't aware lethargy was a sympton. My friend was truly gutted about the dressage usually her horse is more awake when out and about, just wondered if anyonne knew any more?

 

[Paint it Lucky]

I always give my horse 24hrs rest after worming.
If a horse has worms (most do have a few) and particularly if they have lots then they are likely to be in slight discomfort after being wormed as the worms disattach themselves from the lining of the gut which is painfull. Even if you worm the horse regularly she may still pick up more worms from pasture/bedding etc s is likely to have a few at the time ofworming and therefore be in slight discomfort. A horse that's not ben wormed before can get bad colic when wormed as there are so many worms being affected. In future i would make sure you give your mare at least 24hrs off after worming.