“Park regulations also state that pets must be physically controlled at all times. Because the owners of the dog did not have it on a leash, not only did it cause the bison to become agitated, but it also caused a hazardous situation to the owners.”
Friendly reminder that when you’re in the presence of 2,000lbs wild animals with horns you should always keep your family pets leashed (seems obvious but apparently not). KBZK reports the video was shot May 11th in Yellowstone between Grand Prismatic Spring and Norris Geyser Basin. At one point dog is nearly kicked by one of the bison but narrowly missed the blow: