Moving to Ouaga with 2 cats (Ouagadougou)

Salut!
I am Japanese who will move to Ouaga with 2 cats from Niger in the beginning of Nov Protected content to my work.
It would be simple if I bring them to Ouaga from Niger by a car, but I have to go back to Japan once with them because my assigment will be over in the end of July. Then again I will fly to Burkina Faso with them.
Therefore...I am looking for information such as what kind of documents I need to submit at the airport for 2 cats. If you know any info, I would really appreciate.