I'll keep my fingers crossed for Rory. We're in the midst of all the research that is now being done and that's a great place to be if this is indeed SM. There are more options now than there were even a year ago. If it is SM you'll make the decision that's right for you, only you can do that. Our vet is pro-surgery, as he heard directly from Clare that once cases get worse the surgery isn't as effective. That's new information from what she'd intially thought even a year ago. For the surgery, there are two options from what I understand. There is the shunt and then there is the actual full surgery. Our vet said he's had great sucess with only the shunt version, and only once where he's had to go back and do the full surgery. He's also treated mild cases with only meds, but again, it's what is considered mild that is so hard to determine. Abbey's only yelped three times, but there are days that she'll stop 1/2 dozen times to scratch while walking around the block. Other days she's totally normal.
A full MRI is needed for either operation, so that is something you'll need to think about as well in terms of having to have another MRI done at some point if you opt for surgery. Once we get Abbey's lumbar xray back, we'll then know if we do in fact need a MRI. If so, we're opting for a full one just to have all basis covered.
Just some things to think about, but try not to get overwhelmed. You're doing more than a lot of people are, so Rory is very fortunate. Keep your head up and stay positive--you've got a great support system here as well.