If you do not know how much United Airlines Pet Fee is, then you can find out by visiting our website. In United Dogs and Cats are allowed in the Cabin. You can take your dog or cat with you on your United flight as excess baggage in special carrying containers in the air-conditioned cargo hold. The United airlines pet fee of transporting your dog in the hold with United varies, Depending on animal breed and size, they can travel as a carry-on or be transported through United Airlines Cargo.