Thoracic and lumbar transections of spinal cord in ten cats and one dog at varying ages from 2 days to 12 weeks were followed with post-operative exercise of the hind limbs. Some of the animals showed a recovered ability to walk, run or jump in a coordinated manner. Recovery appeared to be directly related to amount of stimulated exercise and inversely to the age at transection. In two animals a second transection was performed, with no detriment to walking. (PsycINFO Database Record (c) 2006 APA, all rights reserved)