It could be many things. Check everything out, tack, pain issues, arena issues. It could be that he is getting sour at it. I never run at home, never. It can cause a horse to sour quickly and easily, cause injury, and cause big time arena issues. The absolute most barrel work I will do at home is slow stuff. Trotting the pattern alot, walking and stopping and backing/turning to disengage the hind quarters when I get to the barrel, making wide pockets when I set up for a turn. Slow easy starting work. Both of my horses stay in shape with alot of trail riding, long trotting, circle work, and ground work in the round pen.
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