Both Caolan and Neala had Umbilical Hernias. Caolan's was big, never caused trouble, but had it removed when he was neutered. Neala's was smaller than Caolan's but hers grew hart suddenly. Of course found out on a Saturday morning. Brought her in and an operation was scheduled for Monday. Not sure what all is in this area, but by her things were bruised and the operation was done just in time. I know there was more than fat tissue involved.
It is fairly common to have hernia's, even if the mom does not chew the umbilical cord. Wouldn't panic, but please check it daily to make sure all is well. Sylvia Katvala with Neala (I like laying on my back) Tucson, AZ