Well, looks like Zoe may have actually gotten a blockage this time. She woke up in the night two nights in a row to try to regurgitate something, but didn't get it up. Then last night, around 10 pm, she threw up...and again and again. When she'd thrown up 4 times in less than 2 hours, including the water she'd drank in between, we headed out to the e-vet.
They took x-rays and said they looked suspicious, like there was possibly something blocking her up. Good news is that it's all in her colon and they believe that she will pass it. Of course, they couldn't tell for sure on an x-ray, so it may just be a virus or something and she's just a little backed up. She was quite dehydrated at this point, however, and we decided to have them hold her overnight hooked up to an IV so that hopefully we could all get some sleep (poor Zoe was feeling too sick to sleep last night; just kept pacing).
We got an update this morning and she hasn't thrown up again and has pooed a little (although she hasn't passed any foreign objects yet). The sleep and fluids have made her quite cheerful so I guess she's livening up the ER today with kisses and a wagging tail (yes, even when she's feeling her absolute worst, she will always wag her tail and go snuggle with anyone she meets).
She will hopefully be coming home this evening, unless she hasn't been able to pass anything yet.
I'll give you guys an update at some point. I'm sure she's going to be fine, but it just stinks when you don't know for sure if it's a blockage or a virus...and we can't even pet our little girl (luckily, she's the type of dog who thrives on attention and is certainly quite happy being a ham for the ER staff....).