JRT Rat Terrier takes off running

by Debbie
(Atlanta, GA)

I got my JRT/Rat Terrier mix at the local shelter, she is approx 2 1/2 yrs old..she has been spayed...her name is Haley. She has been with us for about 3 months now..my biggest problem with her is when she gets loose without the leash she takes off running, can't leave a door open or she will be gone, we have had to chase her quite a ways at times, I have a feeling that is how she wound up at the shelter...How do I stop her from running off or can I?