My Granddaughter who had been living with us moved to southern California to live with my son and family. We sent Daisy, her Holland Lop along in the car. She seemed to be fine with some times out to run, but on arriving in California, my granddaughter took her out to run in the yard, but soon after Daisy was put back in her crate, she just rolled over and died. My son does not put chemicals on his lawn. It is new sod several months ago. Any ideas what happened.