I read that a year or so ago. Lots of....interesting info in there. My oldest read it and asked why the pets were gone. It took her a few minutes to catch on and then quite a bit longer to quit gagging.
Whenever I read about all the pets "disappearing" during such an event I have to think about something I read years ago. Apparently, in a village in England during WWII, The cats and dogs were all euthanized by official order (very traumatic for the pet loving Brits). The idea was that such a death was more humane than letting them possibly get gassed, as the people had gas masks but the animals did not. The end result was that many people lost their beloved cats and dogs for no actual reason, and the village was overrun with vermin - all the mice and rats that the pets had been taking care of before.
I understand how, in an eat or starve situation, my cats might begin to look pretty tasty - but I think I would hold off with the best mouser for as long as possible. Especially if I had a barn full of feed for the "useful" animals I think I would want to have a cat or a terrier helping with rodent patrol.