Bug/Issue How do I get rid of a horse in multiplayer?

Hi, my friends and I are playing 1.3.17 multiplayer, and we just bought a horse. The game started bugging out for my friends, they get stuck on loading screens, they can't open chests ect. Anyways, we restarted the day and I got in alone to demolish the stable at robin's, but the horse is still on our farm and still glitching out the game for my friends, even though the stable is gone. What can I do?

(I'm sorry for the bad grammar but english isn't my first language)