It's happening again.(kle1986)

Is it time for her to come in heat?  Heat cycles will screw up a coat.

 She was supposed to come in 6 months ago. So I guess it's possible. But she's bald in spots she's losing hair. That cant be normal even if she's coming in right?

She has an appointment Friday to get spayed.

ringworm is simply ONE type of fungal infection ... there are zillions.  But generally with a fungal thing the skin will get "funny" -- tough or alligator-like. 

mange?  if it were sarcops she'd be scratching her brains out and demodex you should have seen LONG before this and certainly *not* there first.  (it always starts on the face and would have started when she was a puppy) - they really can't get sarcops on a skin scrape (they're too fast) so ... it's a bit odd that they went that step.

Was it a breed-specific thyroid test?  (like to Dr. Dodds or Michigan State?) or just a local lab (which may not be accurate -- particularly not if she's close to estrus)

 I think spaying with make a difference, if it's not anything diagnosable. Have you heard of allopecia x? It's hormone responsive, and altering them makes it go away, in general.

^ what Jennie said.