In the spirit of sharing useful, if bizarre, information: Someone on the corgi listserv to which we belong recently found their corgi paralyzed at the rear. The vets worked on the dog for about 24 hours, whereupon he suddenly recovered. They could find nothing wrong.
Someone else on the list asked if the dog could have eaten any macadamia nuts - and indeed he had. Turns out that macadamias can cause temporary paralysis in dogs. So, readers with canines, take care of the macadamias.
Our corgis have never had the chance to try macadamias, but they do enjoy Neo's excellent blog Halls of Macadamia.