The airline expects all animals to comply with EU regulations regarding microchipping and possession of a "pets' passport" and holding cages must comply with all the regulations, too.
They have this weird rule that animals must be checked in at the desk (in their travelling box) at the same time as the human passenger, when the animal and box will be weighed along with the rest of the luggage. I've never encountered this with other airlines, but it's there, in black and white, on their site.
They also stipulate that the wish to transport an animal must be submitted to "TCRB N.V." no later than 72 hours prior to the flight. This, they instruct you to do via the "special link" on their website. Now, for the life of me, I can't see any such "special link". I did find a phone number for this "TCRB N.V.", which I'll put at the bottom of this page. Also, there is an email address to the Contact Centre, for special requests, which is available on the site ("contact us").
Other Info
Fighting dogs will not be transported under any circumstances.
Guide dogs will be allowed to travel in the cabin, but must be muzzled and kept on a lead throughout the flight.
contact details:
Telephone: (+32) 9248 4930 Email: via website Website (scroll down to section 7.5)