Aussie Genetics Fact Sheet: Hernia by C.A. Sharp Hernias are bits of tissue that protrude through the umbilical opening. Some hernias in young puppies will go away on their own within a few months, though if one is still present by 5-6 months of age it isn't likely to change without surgery. Sometimes the opening in the abdominal wall is very small, so what you see pushing through is only a bit of the fat that lines the interior of the abdomen. The wall may actually have closed, isolating a small pad of fat under the skin. Large openings pose a danger to the dog due to the risk of a loop of intestine slipping through and becoming strangulated. Such dogs should have surgical correction and should not be bred. Umbilical hernias are inherited. There is a persistent myth that they are caused by the dam tugging on the umbilical cord at birth. This is not true. Dogs with less serious hernias may be bred. Males with hernias should not be used extensively and no affected animal should be crossed to those that are themselves affected or who have a family history of hernia.