I managed to convince my mom to try the Wysong Uretic.... it's not grain-free so I guess we'll see if it makes a difference, but even if it just decreases the vomiting like the California Natural did, that would be a huge improvement over the current situation. And the ingredients don't make me gag as much as the c/d does. I'll also grab some canned Weruva to feed with it.
She's just not open to trying anything that isn't specifically marketed as a urinary health formula and to be honest I'm super shocked she's even open to this! Hopefully it works out well. Good news is Jinx has never been picky about food, so I shouldn't have to worry about that at least.
Thanks for all the help!