I'm sending hugs and purrs, too, Dee.
As for trying the ACV with the prednisone, here's my
: I would
think that it would be ok if you make it a very small amount (e.g. teaspoon or less), as the purpose of the ACV is to add acid to the stomach to improve digestion. This
assumes that the prednisone is somehow reducing his stomach acid. The default by vets and therefore us whenever our furkids have signs of digestion issues is to reach for the acid reducers/blockers, even though the issue may not be too much acid.
That said, I TOTALLY understand your hesitation about adding the ACV, and I think you're doing the right thing. Vlad has gone through enough recently, and you're being careful with him. In 14 days you can see how he's doing without the Prilosec and make a decision based on that whether you want to try adding ACV. If I get a chance, I'll try to research if pred can cause a reduction or increase in stomach acid. I have a hunch that no one's really looked into that, though.
You're doing a great job, DeeDee. Vlad is so lucky to have you!