fwiw, in the 30 years my dad flew commercial aircraft he hauled countless animals*, both in the hold and in the cabin, and he believed strongly those animals were each and every one given priority care. (heh and he said the airlines couldn't afford the lawsuit/insurance if they ever injured a racehorse). 'course, it's anecdotal, and now several years out of date, but still.

*srsly. I tell a few of the best stories, esp the 'Seeing Eye Iguana' and the 'Hoodini Dog' as party jokes.