I'm a newbie on the board but have had my share of hardware (every cow & bull now has a magnet). Agreed, it looks like a fat brisket. In our experience if it's hardware it's not just the brisket; you would see swelling of the legs due to congestive heart failure (think old ladies with their feet bulging out of their shoes) and her legs look fine. You would also see what looks like bottle-jaw and she would lay on an upward incline to get more oxygen. Can initially be mistaken for pneumonia. Feed intake declines and she may walk funny, she will also lag from the herd. That said, our vet does a blood test to rule out tumors, lymphoma, etc - and tells us our cows are a little too fat.