#159 - This is what the bumps look like - Any ideas?

I've been cleaning Teddy's bumps every day (except last night when I was a uni) and there is very little change. Improving slightly. They don't bleed or anything and only one is large, about the width of a pencil. When I pressed down on that one today he did go a little weak in the back and then he stuck his head up from his feed and just looked straight ahead with his teeth together and dribbling the water he had just drunk. He probably stood like that for a good 30 to 40 seconds. I had to go over and have a scratch and chat with him before he went back to eating. Maybe he heard something in the distance that I didn't and he was listening out for it, who knows.

Here are some photos of the bumps. You can click on them to enlarge them.  Let me know if you know what they are. There are 5 on his back,  all around where his saddle seat sits.