i can only relate personal experience in moving a dead dog. Extremely large, 120 lb plus dog, was alive at lunch time, around 1:00 p.m. Was found deceased at 5:00 pm., inside the house. By the time we moved his body, it was around 8:00 pm. Did not notice any noticable rigor having set in yet. It was also summer time, dog was inside air-conditioned home the entire time. I sat in the back of and suv, seats down, flat back of the vehicle, holding his head and upper torso in my arms while we were driven to the vets office. So i think i would have noticed, had it been difficult to manipulate his head, neck, upper torso, into my arms to cradle him as we drove. He was definitely deceased by no later than 5:00 pm. Though. I was cradling him for *my* comfort, not his.