@Libra926 - thank you, that was very helpful. Frank has had periodic episodes of small head tremors but he will always respond instantly to a treat like yogurt, frozen pop, or peanut butter. I know this is very common and has never worried me. However, yesterday he had a short episode where he was shaking his head, foaming, and wasn't very responsive to getting a treat. It only lasted about two minutes, then he was responding to us and was able to lick a frozen pop. He never fell down or anything but seemed a little disoriented very briefly after but nothing like walking into walls. We just watched him very carefully the rest of the day and he has been completely normal since. I don't know what else to do other than just be hypervigilant for any more episodes like that. It really scared me but I wasn't sure if I should be extremely worried about it or if it was just a longer episode of head shaking.