We just heard from the vet that Mo'i is out of surgery and doing just fine. Whew!
Best of all: the surgery confirmed that the problem was exactly what the vet thought it was – fragments of disc that were pinching a nerve the runs to his right rear leg. That means it was not a tumor or any other life-threatening issue.
The vet thought she saw a single fragment on the MRI yesterday, but it turns out that the actual situation was a bit messier. If I am correctly understanding her description, it appears that for whatever reason, this particular disc in Mo'i's back calcified, hardened, and then broke apart into multiple pieces. One of those pieces was pinching that nerve.
During the surgery she cleaned out all the little fragments, then put Mo'i back together. His back is currently being iced to reduce swelling, and he's on good pain medication. They don't want us to visit tonight, because they want him quiet and still. Dang. We'd sure like to see him right about now...
But the important stuff is that he's ok, and we're done with this problem. Even better, the vet says there's no reason to believe that his agility work contributed to this injury in any way, and he's perfectly ok to go back into competition.
We can hardly wait for Saturday morning, when we get to bring him home. And tomorrow afternoon, when we can visit with him.
A big thanks to all of you who sent kind words and thoughts – 'tis much appreciated by these worried “dog parents.”