Update... He has turned a corner and is feeling better!
Joe spent Saturday and Sunday sleeping. I mean, passed out, not moving for hours, sleeping. I gave him his meds as directed (Atovoquone 3 times a day, an antibiotic once a day, an anti-nausea pill once a day) and tried to get him to eat and drink but he was not interested in food or water. Twice he did eat 8-10 cat treats. I was willing to give him anything just so he would eat!
While he seemed uncomfortable and like he didn't feel well, he didn't seem like he was in pain, which gave me big hope! And yesterday morning, I woke up and he wasn't laying next to me, which is where he had been for 3 days. He had moved to a cubby next to the bed. We had arranged with the vet Saturday when we saw her to bring him back in first thing Monday morning.
So after I gave him his meds and got him to eat a few more treats, and we loaded him up and headed to the vet. In the room, after they weighed him and took his temp (down a 1/2 pound but normal temp), he became very curious and spent some time exploring. He even jumped from the floor to the table. Our vet was so pleased! His appetite had her worried, and she was going to give him some valium which kick-starts a cats appetite (she did that Friday and within an hour he had devoured a meal), but since he was literally digging around in my handbag, I thought maybe he was looking for food and maybe we should just try to feed him. She agreed, and brought in some warmed up Recovery formula wet food. At first he turned up his nose, but once the vet and tech left, he jumped up on the table and got back in his carrier. I put the food in there and he ate every bit of it. When he was done, he continued exploring and found the sink. I turned it to drip and he drank for a few moments.
The vet returned and she has released him! Of course, if there are any changes, we should return, but there's nothing further to be done aside from continuing the meds through the end of the 10 days.
Joe spent the afternoon alternating between sleeping hard and sitting at the window watching the birds. I work from home but have gotten very little work done in the last week, because it's obvious he just wants me to sit with him. And I oblige.
My son is thrilled - he was with us at the vet and got to see and hear all of the instructions. Joe "speaks" everytime my son comes in the room, and the only time he has purred in the last week is when my son is sitting on the bed with him.
Thanks so much to everyone for their warm thoughts and prayers for Joe! I tentatively think he has turned the corner and is going to be okay, and I can't think of much that would make me happier!