Good short, but I have a question: what the hell is "I heard a sharp back split through the air." A sharp BACK?! I've never heard a back before. Let alone an air-splitting back.
Did you mean crack?
"My mouth grew dry as my dog lunged forward, ((I)) my arm lurched as it was ripped forward." That "I" is not needed there.
"I thought as I yanked at the leashed and a scream escaped my lips" the leashed...dog? Or did you just mean "leash"?
Oh, it was tense and realistically scary alright, but fix those typos!