We had a dog do that once. Was roaming the side yard when she saw Dad in the front yard among the trees clearing out the draining ditch. Apparently, the dog thought the tree would get out of her way when it saw her coming. Dad said he heard the dog charging through the underbrush, heard the thud, and turned just in time to see the dog fall sideways from behind the tree.
We had a dog do that once. Was roaming the side yard when she saw Dad in the front yard among the trees clearing out the draining ditch. Apparently, the dog thought the tree would get out of her way when it saw her coming. Dad said he heard the dog charging through the underbrush, heard the thud, and turned just in time to see the dog fall sideways from behind the tree.