Harley and I flew 3 weeks ago. ( He will be 4 months on the 21st!) I called the vet before hand to see if there was anything I could give him to calm him down, and he said no because of his size. BUT I will have you know Harley was an angel the entire trip, even for our 2 hour layover in Memphis! He never made one peep on the plane. I wouldn't worry about it. Im sure your baby will do fine!