urinate on bed repeatedly

Question
My female miniature wiener dog is 13 months old. She is just the sweetest thing and was very easy to train. She is fully house trained. She is much loved and sleeps in our bed with us (and our two other small dogs). She is the youngest dog in our household, the other two dogs are wiener cross breeds and one year older.

Recently she started to urinate on my bed. I can't leave her alone in the room for a minute - even to go to the bathroom - or she will jump ons the bed and do her thing.
We are all dog lovers in our home and our dogs live relatively stress free lives. I also took her to the vet and medically there is nothing wrong with her.

Why is she doing this? She is never alone (even if it is just the other two dogs with her) and gets a lot of attention. She is also not anxious by nature.

She loves me dearly and will sit on my lap 100% of the time if she could. Could it be that she is so attached to me that the few moments I spend in the bathroom is enough to freak her out? Should I take her with me?

I work 9 to 5 and when I am at work, the seperation doesn't seem to bother her.

Why is she okay when I leave for hours, but urinates on the bed when I just step out for a minute?

Please help! I am so sick of washing everything in vinegar every second day.

Answer
Here's a well written article on the problem of dogs urinating on beds: http://www.veterinarypartner.com/Content.plx?P=A&A=2456
As you can see, there are various reasons for it.  If it is bothersome, I tell owners to restrict all the dogs' access to the bed for a while, say a couple of months (your dog's arrival at the age of social maturity is also a trigger for this behavior sometimes, so she's just the age where one could expect to see something such as this - possibly telling the other dogs, and you, since you just got out of it, that she thinks the bed is hers).  Use an enzymatic cleaner to completely remove all odor (you may have to saturate the mattress, too, dogs' noses being as sensitive as they are to smells).