Bad news: Pixie is in the hospital - he stopped drinking and eating on saturday, took him in today.
Good news: His bloodwork was fine, nothing wrong with liver, kidneys or his blood.
Likely problem? Salmonella. Nothing you cure, you just got to adress the symptoms or the cat can die.
Edited to add: Salmonella goes away on its own, but a cat can die from the symptoms, so the vets got to treat the symptoms. Bit like a really, really bad stomach flu.
So, one night in hospital and he should be back to normal tomorrow.