The vet technician who was assisting yesterday was very relieved I had brought a urine sample in so that she didn't have to collect it. 
While they ran the urinalysis, the vet came in to give Cosette a physical examination.  She squatted down beside her and ran her hands over her, stopping to feel under her belly and by her uterus.  She then went behind her and swept her tail aside, looking at the affected areas.  She abruptly stood up and said, "Let me go get a light.  It's kinda dark down there."  I laughed and said, "I imagine it would be!"  While she went to collect a light, I brought Cosette into her standing position ("Stand") and put my hand  under her belly, her butt facing the door.  The vet walked back in and knelt down, and Cosette looked back to see what she was doing.  The vet spent several long moments examining her, and then stood up and said, "Her vulva is quite inflamed, probably from all the licking she's been doing."

Cosette, your vulva.  VUL-VA!  Why have you been licking this area?  I guess I would too if it stung when I urinated.  Wait, I can't reach it, that's why. 

The vet went to take a look under the microscope, and meanwhile, I kept saying it in my head:  VULVA.  Your VULVA is inflamed.  I felt a little bit responsible, as if I had needed to try and keep your VULVA untouched by your tongue.  Vulva.  Inflamed vulva.  BAD vulva!

The vet came back with the results, lots of white blood cells and a few red blood cells in your urine.  Bladder infection.  Hot damn, I was right.

$140 later, I was all, DOG, DON'T YOU DARE LICK YOUR VULVA.  At least take it into the bathroom so I don't SEE YOU DOING IT. 

 

I've made an appointment at the vet this morning for Cosette.  She's been urinating very frequently while we're outside on trails, and the other day she urinated right beside me in my office.  It scared her when she did it, too; she went to sit down and the urine came out.  She flung around, scared out of her mind.  I lightly said, "No," and took her outside, knowing that something was wrong.  She's been house-broken for a year and a half, so any sudden changes in bathroom behavior is most likely a health issue.  Then, last night, I let her out before I went to bed, and she urinated three separate times in the yard.  She then came inside, acted sheepish, and urinated a little bit on her bed.  Poor baby.  I'm guessing she has some sort of urinary tract infection or a bladder infection.  I know what it feels like to pee fire and to constantly feel like you have to go - UTIs are awful. 
Cosette had one right after her spay surgery, and these symptoms are fairly familiar.  Off to go get a urine sample from her, and take her to the vet...