
This is what Delta says
Pets As Carry On
Some pets can travel with you in the cabin for a one-way fee of 125 USD/CAD* (to be collected at check-in) for travel within U.S./Canada, U.S. Virgin Islands, and Puerto Rico (200 USD/CAD/EUR* for travel outside the U.S.) with the exception of any travel to/from Brazil which is 75 USD one-way. For any travel to/from South Africa (in exception of service animals) pets must travel as cargo and are not permitted in the cabin or as checked baggage.
Pets permitted in the cabin include dogs, cats, and household birds. The following restrictions apply:
* Your pet must be small enough to fit comfortably in a kennel under the seat directly in front of you. Maximum carry-on kennel dimensions are determined by your flight. You must contact Delta Reservations to determine the appropriate kennel size.
* Your pet must remain inside the kennel (with door secured) while in a Delta boarding area (during boarding and deplaning), a Delta airport lounge, and while onboard the aircraft.
* Your pet must be at least 8 weeks old.
* You may not carry on more than one pet.
* Your pet in-cabin counts as one piece of carry-on baggage.
* If you're traveling to Hawaii, your pet won't be able to go with you in the cabin, and other restrictions may apply. See Pets to Hawaii for more information.
* Pets are prohibited in-cabin and as checked baggage into Hong Kong and the United Kingdom. Pets may only be brought into HKG and the UK as cargo.
* *CAD amount will be charged exit Canada, and EUR amount will be charged exit Europe. Fees established by the contract of carriage in effect at the time of ticket issuance will apply.