Havs tend to be jumpers. Some of them don't ever really jump - like Timmy, above - but the ones that do, usually DO! And from what I've read on this forum, some of them are just born to jump, and there isn't much you can do about it. Those of us that have jumpers try to keep them from jumping on/off of things for at least the first year to keep them from injuring themselves, but I know from personal experience that you can only do so much. I never encouraged Cey to jump when he was younger, and for the longest time even discouraged him for all of the reasons that Starr states above, but jump, he did - and does, and has ever since.
The top of my bed's top mattress is 28" from the floor. At the top of his shoulders, Cey is about 10 1/2" tall - and he has been able to jump to my bed from a standing start
- EASILY - since he was about 7-8 months old. I swear he has springs in his legs, not bones like a normal dog! (I've always had to use a 'double' baby-gate sort of situation to keep him contained, as he has been easily able to jump over a single baby-gate since he was just a few months old...)
Anyway, from what I can tell from what you've said, I suggest getting used to it
. Try to keep him safe, of course - at least for the first year, try to put him down instead of letting him jump down from heights, and so on. But, IMO, if you have a jumper, you have a jumper. Anything that you don't want him to get into that is within jumping distance, you have to actually train him not to jump onto - you can't rely on him not being able to get up there!
Boing, boing boing