If your dog has started dragging his hind legs, he’s going to need to see a vet, as there are several possible causes of rear limb paralysis (paraplegia) and partial paralysis (paresis), all of which need medical attention. You’re also going to need a diagnosis to know which of these problems your dog is facing, what you can do to help and what the long-term prognosis is.
Signs of paresis and paraplegia
Paresis and paraplegia may be acute, in which case your dog may be moving around normally one minute and dragging his rear legs unable to move them the next. Or it may be a chronic condition that gradually develops over time, in which case he may begin by dragging his toenails along the ground or running with a "bunny-hop" gait (using his rear legs together to gain more strength) before he loses the ability to use them altogether. Other early signs of degenerating spinal or nervous conditions include pain and stiffness in the neck, spine and legs, an inability to urinate or control urination, and constipation or straining while defecating.
Causes of rear limb paralysis
Your dog’s spine, brain, nerves and muscles all need to be in working order for normal movement, so injury or trauma to any one of these could cause the problem. Similarly, diseases and infections or genetic conditions effecting them could be the cause of paralysis.
You should also check your dog for tick bites, as these can also lead to paralysis. In any case, if your dog is having difficulty moving any of his limbs, you should treat it as a medical emergency and get him to the vet as soon as possible. With many of the possible causes, speed is imperative in diagnosis and treatment.
Diagnosis and treatment of paralysis
Through a thorough physical examination, blood work to check for bacterial and viral infections, and x-rays, to check for tumors, slipped disks of malformation of the spine, your vet will usually be able to tell you what the problem is. In some cases, CT or MRI scans, biopsies of muscle or nerve tissue, or samples of spinal fluid may be required.
Treatment will depend on the diagnosis. While some causes of paralysis may be treated with medication, surgery or simply time to heal, others are irreversible. If this is the case, your vet will discuss the possibility of long-term care and quality of life with you. Some dogs are able to live long and happy lives despite rear limb paralysis, thanks to devices like a supportive cart that gives them their mobility back.