The US airline Delta does not allow service and support animals under the age of four months to fly . All emotional support animals on flights of more than eight hours are also prohibited .
The new policy will be effective as of December 18 .
Delta made the change after discovering an 84% increase in incidents involving service and support animals in 2016 and 2017 . Incidents include urination, defecation and biting of certain animals while the planes are in the air.
The airline says its new age requirements align with the CDC (Centers for Disease Control and Prevention) vaccination policy. Delta says it will contact customers to adjust bookings if policy updates affect their future trips.
