My frenchie has done this twice already. He was sleeping at around almost 12am and then i could feel the bed vibrating and when i went to check on him, his back legs were sort of bouncing but i dont think its his back legs actually bouncing.... it looked like his back was hunched because he was gagging but he also wasn't gagging. Looks like he was having uncontrollable movements in his back. It looked like a muscle spasm/ seizure. But the first time i took him to the emergency vet when it happended they said it might not be a seizure because he was repsonsive and still very active after it happened. And i am 100% sure it wasnt him dreaming because i know what i looks like when hes dreaming. Has anyone's frenchie done this or something similar. Any advice would be helpful please. Thank you in advance