Wounded by any other animals? Friend just lost a bull with those symptoms. Turns out the bull got rammed by a rival bull and cracked a rib. The cracked rib ended up puncturing a lung and killing him rather quickly.
Sounds like a massive pulmonary embolism to me???????? Was the blood bright and forthy, or dark and smooth no bubbles? How much blood was lost a lot or a little. Did the bull injure itself in anyway? How old was the Bull? Any Stress or just out in pasture. Did you have a vet preform an post on the animal?