(a) Except as provided in §14.106(j), ventilation openings must be located on at least two walls of a primary enclosure. When the required ventilation openings are located on two opposite walls of the primary enclosure, these ventilation openings shall comprise at least 16 percent of the total surface area of each ventilated wall. When ventilation openings are located on all four walls of the primary enclosure, the openings shall comprise at least 8 percent of the total surface area of each wall. At least one-third of the minimum area required for ventilation shall be located on the lower one-half of the primary enclosure and at least one-third of the total minimum area required for ventilation shall be located on the upper one-half of the primary enclosure.

(b) No more than one elephant or ungulate shall be transported in a primary enclosure, except that: a mother and nursing young may be shipped in the same primary enclosure if the shipment complies with the provisions of §14.105(b); in the case of land or sea transport, a pair of juvenile elephants or ungulates or other pairs that have been habitually housed together may be shipped in the same primary enclosure.

(c) A primary enclosure used to transport an elephant or ungulate shall be large enough to allow the animal to lie or stand in a natural upright position with the head extended, but not large enough for the animal to roll over.

(d) A primary enclosure used to transport an elephant or ungulate with horns or tusks shall be designed and constructed to prevent the horns or tusks from becoming trapped or injuring the animal itself, other animals nearby, attendants, or cargo handlers.

(e) A primary enclosure for an elephant or ungulate shall be equipped with a removable water trough that can be securely hung within the enclosure above the floor and can be filled from outside the enclosure.