We've got a sick heifer, Rosie, who two days ago came down with some sort of respiratory disease. She has a runny nose, dripping really, and now it seems to have moved to her chest because today she's coughing. Southern States guy said to give her a one-shot broad spectrum antibiotic. Tetracycline I think. We're to give it sub-cu. Does this advice sound good? I'm for calling the vet but he seems to think this will knock it out without a problem. And by the way, isn't it odd that she got this diease? She's with only one other cow who is healthy. Nothing's come or gone from our farm, no other cows for miles around. No stress, no change in diet... I thought cows were tougher than this... specially longhorns!