Laura, I'm so sorry to hear things aren't better for Corkscrew.

My suggestions, if you're not quite ready to give up yet, is either an ultrasound or x-ray, like Catty1 said. I think you mentioned that he was x-rayed, so maybe try an ultrasound this time. You just never know what might show up - either good or bad.

{{{hugs}}} and thoughts and prayers sent. I know how stressful all this can be on the human component, especially when things start getting more and more expensive, with no cure in sight.

{{{hugs}}}