And put her on the cull list….leave it alone.
Get her in a headgate or squeeze and milk that teat out. It's just engorged. The quicker you get it emptied the less likelihood of problems. Once it's been milked it's likely the calf will suck it down just like the rest.I have a cow that has a large tit on one side. She has a new born less than two weeks old. Should I leave her be or catch her and what then? See pics I hope. View attachment 17637