Barbara, it often works that way with the sudden breakthrough. It seems like they can get sort of a glass floor with the higher #s, and it takes a little extra insulin to break down through it - when you get the breakthrough it can be quite sudden and dramatic like that. The trick is to get the breakthroughs w/o overdoing it, and then not overreduce and lose the good #s, while at the same time not overdoing it.
You may find after this that a dose like 0.5 works perfectly, when before it wasn't working. It's all a big mystery, but we see these kinds of patterns a lot. That's one reason we sometimes argue over things :mrgreen: since the results can be so dramatic we tend towards caution a lot of the time. But if you are too cautious sometimes you never see the breakthroughs, so it's kind of a tightrope act. Thankfully Thumper's doses are quite low so there's less of a nailbite_smile factor over actual hypo.
Hope they find 0 ketones at the vets. Ketones be gone!!! :evil: