We shipped via American but, you cannot book more than 10 days in advance and they will not ship an animal if the temperature will be 85 degrees or above at the departure airport, any interim stops, or in San Juan. They do not ship at night and they will also not ship on a flight departing less than 3 hours before their cargo area opens. In Miami, the AA cargo opens at 5AM so no shipping earlier than an 8AM flight.
I think it will be hard to ship for the next several months.