How did he feel for the foal?
I have just called the vet again, and mentioned the photo and ventral rupture and he said he would definatly be here in the morning, She only looks like the white horse, not the others. It may be that the foal has dropped into a strange position, but I am surprised she hasnt foaled and want him here whatever. Better to be safe than sorry.
My farrier/trainer just felt her all over, not internally as he didnt have any gloves. He felt the "tire" shape too. I have tried to call him but he no answer.