As I've said, the regulations were amended in 2019 to offer additional protections and measures to prevent avoidable suffering in animals that are being transported, including horses. There are provisions for air transport also.
The regulations provide for adequate space and for proper training of those transporting, as well as speak to container closure and a reporting mechanism to CFIA should something go wrong during transport that results in death or significant injuries.
I have confidence in these regulations, but as I said before during the study on electronic logging devices, transporting animals is complex, and unforeseen events do happen. Contingency plans are required of the transporter, and there are times when the regulator and the transporter or regulatee must make decisions in the best interests of an animal's welfare.