Hi, I'm sorry you're going through this with your baby. I don't have any experience with seizures, but hopefully some members with experience in this will come along soon and be able to give you some information or advice. It still could be caused from him playing too hard, and him being winded after play. I have two EB's, they are siblings, and they can horse play pretty rough with other sometimes, I have to watch them when they overdo it, and they start to pant, they haven't had the symptoms that you described of not moving, but they will pant a lot and start to drool, and then I know they've had enough playing or running around. I separate them and make them lay down, one will usually jump up beside me on the couch, and the other on the other couch, or they will both just lay on the floor but in different spots, and they will pant for a while, and then slowly their breathing gets back to normal and they will sleep for a long time. I really watch them for this, and I don't let them play like that outside unless its early in the morning and not hot, or on a fall day when the weather isn't too hot. I hope it's nothing serious, and he's okay. Sending love, hugs and prayers your way. Please keep us posted on what the vet says.