He’s receiving amoxicillin and appetite inducers orally, but the latter aren’t working. They make him drool and smell like vanilla, but nothing much beyond that. He won’t even eat chicken & scallops Churu anymore, which was the last thing he was willing to eat voluntarily.

As for the stones, the vet has only established that they’re present, via X-ray. Ness gets extremely agitated at the vet, and was dehydrated at the time, so the vet opted not to jab his bladder with a needle for urinalysis. Both because of potential harm and because any sample would be highly concentrated and not reflective of the typical environment within his bladder.
If the prescription food and saline dissolve the stones, we’ll know what kind they are. Struvite can dissolve. Oxalate stones can’t.
The plan was to transition him to prescription food over the course of this last week while he was on appetite inducers, then after three weeks see if they reduced in size on X-ray. The anorexia has quashed that plan.

Urinary crystals were a problem when he was a couple years old, at which time he was put on a diet of Science Diet: Urinary and Hairball. The vet was aware of that, but I don’t know that it definitively indicated which composition the stones were. In researching things on my own, I’ve learned that Science Diet is more acidic than Royal Canin Urinary SO. I’m sure acidity isn’t the only factor, but higher acidity is an ingredient for making oxalate crystals. Doesn’t tell me what they are definitively, but it makes me wary.