My mother has an8 year old Burmilla (Burmese/Chinchilla x). Every 2 or 3 months he collapses, his breathing becomes erratic and fast, sometimes to the point of open mouth panting (but with no sound), he does not go unconscious but he is not aware of his surroundings. He sometimes cries out like a howl, loses control of his bladder and poos himself and cannot stand properly. The howling sometimes continues from time to time throughout the episode. It can last 30 60 minutes and then he gradually returns to normal. The vets have carried out loads of test but can find nothing wrong. They have prescribed PREDNIFOLONE to help with his breathing if he sounds like he is struggling but cant offer any other advice. He feels cold and his paws feel clammy. His eyes are open but unfocussed. This has been going on for about three years and seems to happen every 2 or 3 months. Any suggestions on what this could be?