Useful guide on Dell AA22850 AC Adapter Cord Repair
Leave your last connection without any electrical tape on it to make sure everything works
. You may want to carefully test your Dell AA22850 AC Adapter now in order to make sure that all the connections are secure. Plug the Dell ac adapter into a surge strip and keep your hand on the power switch to make sure you can kill Dell AA22850 AC Adapter power quickly. If everything works, move the heat shrink tubing up over the connection and use your soldering iron or a hair dryer to shrink it up. Keep moving the heat source so that the tubing doesn't melt apart. You have hopefully successfully repaired your laptop ac adapter for now. Hopefully the cat won't eat it too many more times!
Useful guide on Dell AA22850 AC Adapter Cord Repair