My four year old Viszla has started biting at the air for no reason. He does this mostly at night and keeps us up from about 10pm-2am before calming down. He feels better under the covers. Vet thought it was allergies and we've tried Benadryl and Claritan that didn't work. He's been on Prednisone for three days and I've seen no improvement. Internet research is pointing towards seizures. Any insight would be appreciated.