I'm an animal student, I'm not a vet but I have worked in a few. Seizures are usually signs of brain damage especially how you have described it! You do not get such severe seizures from food so ignore them comments, if it was food or anything else/mild poisoning your cat would just be ill and you'd notice a change in behaviour as well - not a seizure!
Your cat needs to have a scan! Without a doubt, go to a better vet who will pay more attention to this!! Your vet is obviously rubbish.
Also, if it helps, through experience I have found that older vets don't tend to pay animals as much attention, they get the animal in and out asap and get their money. It's as though they are just waiting for retirement lol younger vets tend to be more in touch with their job and use more up to date methods. Either way whoever your vet is, they are not giving your cat the correct treatment.
Also, some advice if it happens again - try and hold her down so she doesn't hurt herself, try to keep her airways clear as best as possible and constantly check her breathing. When she comes back round try to keep her stress levels down by not leaning over her.
Her body temperature will also be very high so she will need water. That also explains why she has been drinking more.
Last edited by xXHolly_90Xx; 19-06-2012 at 20:47.