Toy Rat Terrier in Heat?

Question
We have a Toy Fox Terrier.  She is 10 months old and we think that she is in heat.  She has a watery bloody discharge, that ends up on her legs and where ever she lays down.  Her vaginal area is very swollen.  Probably 5 times the size it was before.  Does this sound like she's in heat? And how long can we expect her to stay in heat?  Also, how often do they go into heat?  

Answer
OH YES she surely sounds like she is in season.  They last about 28 days and happen every 6 months.  KEEP ALL MALES AWAY from her.  Don't trust panties on females.  Don't trust chain link fences.  Don't leave her in the yard alone.  Males will dig under.

SPAY and NEUTER your pets.
Tammy