Well, my little kangaroo jumps from stand and I'm definately not encouraging it because the last thing I want, is a dog with bone problems. But she just keeps on jumping, especially when we're at the doggy playground in the morning. There the dogs run (and jump) around and the humans walk a bit, so usually the dogs are too busy to listen to any commands.
I'll try to get her to understand the 'no jump' command though, it might help.
Thanks!