Loss of function of one or more limbs can indicate damage to nerves, spinal cord or blood vessels.
Dachshunds, other long backed dogs, Dobermans and other breeds are prone to degenerative disc disease; discs can rupture and put pressure on the spinal cord leading to pain, then loss of function, usually affecting the back legs.
Any dog, or cat, dragging their rear quarters or any limb warrants early treatment to improve chances of full recovery.
Animals that have sustained trauma may rupture discs, dislocate vertebrae or fracture the spinal bones…causing damage to, or even severing, the spinal cord.
Some of these patients can be repaired and rehabilitated to full recovery. Trauma of any kind can damage nerves to a portion of leg or a part of the body.
Dogs can sometimes sustain sudden pain and loss of function secondary to clots to the spinal cord, called fibrocartilaginous infarcts.
Cats, and rarely dogs, can throw blood clots (called thromboembolisms) related to heart disease or other factors. These blood clots often end up obstructing blood flow to the rear legs, leading to pain, then loss of function and stiffness of the rear limb muscles.
Treatment is complicated and successful recovery is uncommon, but possible. Treatment has to include investigation and treatment of the inciting cause, and measures to reduce risk of repeat clots.
Cats that throw blood clots are usually affected with various forms of heart dysfunction, called cardiomyopathy.