Back (spinal) problems are not common in cats. If your cat has a spinal problem they may have neck or back pain or show a variety of signs including difficulty walking, jumping, using one or more legs or even complete paralysis. These signs may occur suddenly (acute spinal problem) or more progressively (chronic spinal problem).
Many different spinal problems (slipped disc, fractured spine, spinal infection, spinal tumour, ischaemic myelopathy) can cause similar signs. Ischaemic myelopathy is only occasionally seen in cats but comes on very suddenly without warning and can be very frightening. If you suspect your cat might have a spinal problem (especially an acute one) you should make sure your vet checks them over as soon as possible.
Read Ischaemic myelopathy