My parents have a lab that has seizures. At his worst he had them a couple times per week. They kept a seizure log and figured out the seizures generally happened when he got too excited or startled. The vet put him on phenobarbitol and the seizures are controlled now. He has them maybe once a month at most. I know labs are nothing like yorkies, but just thought I would share.
I hope you're able to find a cause and effective treatment for Winston. Poor little guy.
