Since it appeared later on, and is hard, and red, I would suggest getting it fixed. Most of the umbilical hernias I have come across are pink and soft-no matter the size. I find it highly unusual, and I don't mean to scare you, that it is hard and red. I would get it fixed asap. Just my opinion.
I agree that the presentation is more likely indicative of strangulation, and the appearance beyond infancy is additional evidence of a problem. I too would get it fixed asap and forget about acking on another procedure to save costs. A dog with strangulated bowel doesn't need additional stress.
