Sonic passed away today.
She wouldn't eat on her own, then she stopped drinking Sunday. We kept syringe feeding her until we could make an appointment for her. Then we got all the way to the vet, signed the papers for euthanasia. . .and when I went to pay my bill she decided to go on her own.
Garnet is still doing pretty well. She started eating again the next day, so I think for her it was just an upset stomach from missing the Pepcid.