@Motala - That is good that you talked to Jan and glad to hear that she had not been spayed. I still think that your Vet and you should connect with Dr. Gonto about your girl's blood work and blood gas results and if he has any thoughts about it.
Welcome to you (P…) and Benji, so pleased to see you on here!. I hope the seizure was a one-off but i'm sure you'll get plenty of valuable advice here if not. Do get in touch with M & L they have a wonderful vet for Skipper in Oswestry.