is Skipper (move over Mary Beth... your Skipper has competition!). Watch this video closely.... see how Bailey skips (raises his rear end up when he 'trots'?)  Sometimes he skips on one rear leg... sometimes the other rear leg... and sometimes holds both of them up for a split second.  Bailey is obviously not in pain and this doesn't hamper his activity in any way. I've talked about it before on the forum... when he first started doing this, I figured he has the luxating patellas... but after three vet opinions... and two ortho vet opinions....and having everything x-rayed on this dog I can have x-rayed ... all to the tune of almost $1,000.... he does NOT have luxating patellas at all and no one can determine why he does this. I didn't want to continue agility with him if I thought I would harm him in any way... Anyway, I recorded this earlier and wanted to share. IF your dog begins skipping this way, please have him/her checked for knee issues. This is a sign of problems... but it can also be a "terrier thing" (so I'm told). But better to be safe than sorry!  Bailey is what is known as "post-legged" (not enough angulation in the rear legs... see how straight his rear legs are?), so the vets feel this is a habit he has picked up to compensate for that somehow.