I had a 1st cross bitch about 8/10 year ago. Do not know if it was copper t. but at about 6 month she started having fits/seizures, had her checked over by the vet who said she was healthy. (i didn't know about the copper t then). I ended up giving her to an old lady as a pet at about 18 month old as it became apparent the exertion/excitement were triggering these episodes more frequently. If i had known about it then i would have had her tested because having now heard of copper t. I've often wondered.