What Causes Whooping Cough And Shortness Of Breath In Children?

I have a child who is showing most signs for Whooping Cough. If the severe cough and shortness of brath is not accompanied by fever at this time, could it even be Whooping cough. His symptoms began about 3 weeks ago; at that time he ran a fever. We took him to the doctor and he was prescribed antibiotics and Children s Tylenol.