The present invention relates to a folding device (1) for the transport of an animal such as a dog. The device may be located in a folded and in a folded-out state, and the device comprises a rectangular bottom (2) with- two long sides of length L；- two short sides with width B, and- corners.According to the invention, at each short side of the device rigidity-providing wall portions (14, 15) are provided at the location of at least one of the corners, which stiffness-providing wall portions can be secured to the second side walls, which stiffness-providing wall portions are hingable about an axis transverse to the rectangular bottom at the location of the relevant corner for increasing the stiffness of the second side walls.
