Our dog, for the first time, got out of the house to see one of us coming in, saw the chickens & chased one of our RIR until...she decide (with the whole family yelling at her) she'd better stop. We are now in search n' rescue mode it seems as we are searching the last barn we saw them go around. We took the rest of her flock (8) out near that barn to see if she might rejoin her group. No luck. We have weeds & a fence row around so we are looking there, rechecking buildings. It will be dark here in about 1 1/2 hrs.
Pretty sure dog did not 'connect' with her, but they were both 'moving'.
We're new to chickens this summer. I imagine she might even be in shock. ...can they have a heart attack from?
Okay, off to rejoin my family in the hunt.