My 15 week old bernese mountain dog is having a hard time with potty training

Question
Hi! I got a bernese mountain dog about a month ago. I got her from a local pet store. She is very sweet and intelligent.  However, she cannot usually hold her urine in for more than four and a half hours.  The longest she has held her pee in was five and a half hours and that was only one time because she was napping and playing with her toys while under very close watch.  When she is in her crate, she sometimes pees an hour after she went potty outside.  I have had dogs before, and this is very different from my other dogs. I feel that she should be able to hold her urine in for at least 6 hours by now. The vet is treating her for a UTI (however, they never tested her urine so the vet doesn't even know if she actually has an infection). She has been on antibiotics for four days now and had an accident in her crate in the middle of the night and she was only in her crate for 5 hours.  What should I do about this? She is very smart and always runs to the door if she has to go out to poop and once in a while she will go to the door if she has to pee.  Is she being spiteful and peeing in her crate for attention? Or does she have a bladder issue? I would greatly appreciate any help I could get. She has another vet appointment in about a week and a half so I will be talking to the vet soon. But until then, any advice would be appreciated. Thank you so much

Answer
She's definitely not being spiteful!  A normal, healthy puppy can be expected to hold its urine an hour for each month old.  So, your pup might be expected to hold it for almost 4 hours IF she doesn't have a UTI.  An infection will definitely cause more frequent urination.  

I'm not sure why she'd be on antibiotics if a UTI hasn't been confirmed.  I would certainly follow up with this.  Did she have a fever that indicated an infection was present?  Antibiotics can also make housetraining a challenge.  

Once this is all cleared up, you can start over with housetraining.  You do have another challenge to overcome, though.  Pet store puppies are used to eliminating where they sleep, so the crate become just another place to potty. They don't learn to keep their "den" clean because they have no other option but to soil it.

Clean the crate out well with an enzymatic cleaner.  Maximum crate time for a dog this age should be 4 hours during the day.  Once she's healthy, you can probably expect her to hold it overnight.  Be sure she's getting enough exercise during the day so that she's tired out and sleeps through the night.

Make certain that she's pottied outside before she goes in the crate when you leave or before bedtime.  If she doesn't go when you take her out, put her in the crate and try again in a half hour.  

Puppies need to be taken out after play sessions, after waking from naps and every half hour while they are awake.  Prevent accidents so they don't become habits.

I think the trouble you're seeing right now is either attributable to the UTI and/or the antibiotics.

Please let me know if you have further questions or need clarification.  Good luck!