Well we still haven't got the test results back, but Yogie continued to have seizures so we put him on the epilepsy medication. It's been 2 days and he's totally fine! I really thought he was going to die, but now he's stable. Uggh he just licked my lip (he's on my shoulder). I still don't know whether it's epilepsy or zinc poisoning though, because the medication would still control seizures caused by zinc poisoning. The results should be coming through within the next couple of days.
I'll post this on the other thread discussing seizures, but good news, the test came back negative for zinc poisoning. Everything else has been ruled out, so it must be epilepsy. And that's fine, because the medication is controlling it perfectly. Lucky Yoges, I don't think his previous owner would have bothered to medicate a sick bird.