As it turns out, repatriating your pets is in some ways easier than repatriating yourself. Take my example. For a one-way cattle-car-class ticket from Addis to Washington I paid $1300. Because the tiny seats don't have enough leg room for full-sized people and don't recline more than a few degrees, I'll be lucky if I get a couple of hours of sleep out of the whole journey. I have an eight-hour layover in Amsterdam. Since I'm on an economy class ticket, I don't get use of the airline lounges. So I can roam around the crowded waiting rooms, cooling my heels until my flight boards.
Compare this to Toby (dog) and Janet's (cat) experience. They go as excess baggage, $150 each. They go in their crates with soft blankets in the bottom, in which they can curl up, stretch out, lie flat, and sleep. In Amsterdam, KLM collects them and takes them to the pet hotel where they can exercise, snack, and relax until they go to the next flight, all included in the $150. No word on whether they get a massage and spa treatment.