Live unattended cargo on ULR flights

[Fluke]

Just completed a 16.5 hour flight, probably closer to 19 hours with delays before departure. (Max duty is 22 hours with four crew). One of the delays was caused by a missing pet dog. While cursing the unexplained circumstances it occurred to me how sensible it was for the company to be loading animals into the hold on flights with this sort of flight time. I couldn't find any limitations or policy anywhere but then again they are very new to this type of operation. Any comments ?