Our little Maltese Cross is on Gabapentin. He had acute pancreatitis and is recovering well. He also has a sulaxating patella and cruciate trouble. The vet said the Gabapentin would help with both. The pancreatitis is under control now but he is still limping a bit, surgery will be needed soon we reckon.
That said, Gabapentin is well tolerated in most dogs. The only side effect we saw was a bit of lethargy when he first started on it. We don't see any problems with it now.
We considered using Golden Paste but we're worried about the fat in the oil. With his pancreatitis he is on a special low fat diet. I think you need to be careful with fat levels in Cushing's so that you avoid pancreatitis and other complications. I know there are good fats and bad ones but we didn't want to take any chances (our vet even told us to take him off the green lipped mussel supplements he had been on.)
We have used Rosehip powder as well. You can get a canine version but it's exactly the same as the human one sold here in Australia. I would say it made a little bit of difference, but not a huge difference. It helps reduce inflammation. I couldn't find any drug interactions or contraindications with pancreatitis so we've used that. Our canine version comes in a powder that we mix into wet food. Our boy doesn't love it to be honest. You might be able to get it in pill form.