I mashed the knot today because it looked like it was coming to a head. There was pus and blood in it, and it went down almost entirely.
I wonder if I can get some info online about the anal glands until I can get into see the Vet? Thanks for knowing what this might be. I was afraid he might have a spider bite, or ???, but your explanation fit so well.
I am really thankful the Breeder told me about this Web-site. All of you have been so helpful. I am a horse-person, so this has been a big transition for me, and I am loving every minute of it.