Originally Posted by Honez

Honestly? Sounds like you need to go to a new vet. The seizure and vomiting are both possible reactions to the deworming meds he gave her and just because HE has never seen an adverse reaction in 20 years, does not mean they do not exist. I highly doubt she has a dead parasite in her brain although I would bet that she had an underlying illness (which is why you took her in) that he did not find so he just decided to deworm her and hoped that would "fix" her. By the way, did he even test her for heartworms before prescribing heart worm meds?

When she comes out from under the sedation and is strong enough to move, if I were you I would take her to another vet. This guy sounds a bit clueless.