A girlfriend's cat once ate the mylar "string" that was attached to a helium mylar balloon. The string must have been 5 feet long and unfortunately, something that long and undigestible pretty much got stuck somewheres inside the cat (named Differ - because we found it under a car sitting on the differential). Differ stopped eating and was getting listless. We too her to the vet, but he could find nothing wrong. a day later, my girlfriend noticed Differ coughing occasionally and caught sight of the end of the mylar strip hanging out of her mouth. Mt girlfriend pulled it gently and eventually got the whole thing out. Thank goodness it started coming out in THAT direction...

pax yall