I need help.  My Lilliput has issues with crystals in her urine.  I need to test her again.  But she has caught on to my intent to collect that sample and will absolutely not allow it.  In the past, I could sneak behind her with a shallow plate in the yard.  But now when a person comes near her she goes into play mode.  She won't pee near a human.
So I've tried taking her on a short leash with a small baby food container. This has a lid so I can bring it back from our walk.  But she is on to me.  She has developed a "squirt" technique.  In the middle of walking there's a quick little squirt then she bolts. Sometimes right in the middle of the sidewalk. Not enough time to get down to her level.  If I have no container, she will sniff and pee as usual.
She is in general a dog who does not want people to do anything to her, so this isn't really completely surprising.  I TOLD her that if she would pee in a cup I would take her to the park, but even that didn't work.
So how do I get a sample from a short dog who is determined not to let me get it?  I don't want to do a clean catch again if I don't have to.