See below from a previous thread on back problems in beagles. 11 months is a little young for disk lesion but injury could precipitate it. Of course there are other possibilities. Examination by DVM is suggested.
Beagles are at risk for developing intervertebral disk lesions. The material from degenerated intervertebral disk (the cushion between vertebrae) can compress spinal cord. This results in pain and sometimes paralysis. It may be associated with injury in some cases but often is not associated with any known injury. Steroids and cage rest are often effective. However some dogs require surgery or in some cases do not recover. The outcome may depend upon the extent of injury to spinal cord and this may vary in each individual case. .