More information than you ever wanted to know about the health of my cat, but I feel the need to type it out, so deal. Besides, it let's me update several interested parties at once. If yer not one of them, stop reading now.
Sunday night, Boo still wasn't feeling better. His appetite didn't return and his breathing became more and more labored so I took him back to the ER. This afternoon we got confirmation of his situation.
As it turns out, it's a combination of cardiomyopathy/congestive heart failure and regenerative anemia.
The heart failure is likely due to a pre-existing condition that was exacerbated by the stress of the surgery, the anesthesia, the medication or a combination there-of. The heart failure caused fluid to leak into the chest cavity, thus causing pressure on the lungs not allowing them to inflate fully. (No stranger to lung/breathing issues, I find it all too easy to empathize with him.) They've drained 63ml of fluid, but some of it has built back up.
The anemia is possibly caused by blood loss from the surgery, but might also be due to his immune system reacting poorly to the the anesthesia, medication or even just the stress of the heart failure.
Besides the fact that each of these is, on their own, a serious life threatening illness and besides the fact that the combination together is very grim... there's also the possibility that treating the anemia could *cause* heart failure. Ain't that a fucking kick in the teeth?
Boo is very far from out of the woods, but he's still fighting. However, it's his call and if he decides to stop fighting, we won't make him. His quality of life is also of the utmost concern. It's tough to see him suffering, even in the short term.
Thanks for the kind and supportive words.