SYMPTOM
Hind leg paralysis in cats
Sudden inability to move one or both hind legs, sometimes accompanied by cold paws or vocalisation.
Aortic Thromboembolism
One of the most recognised causes of acute hind leg paralysis in cats involves the formation of a blood clot that lodges at the aortic trifurcation — the point where the aorta divides to supply the hind limbs. This thromboembolic event abruptly interrupts blood flow to one or both hind legs, producing sudden onset paralysis, pain, and characteristic changes including cold limbs, absent pulses, and pale or bluish nail beds. The condition is frequently associated with underlying heart disease, though the cardiac condition may have been clinically silent prior to the embolic event.
Spinal Cord Disease
Conditions affecting the thoracolumbar or lumbosacral spinal cord can produce hind leg paralysis through compression, inflammation, or vascular compromise of the neural tissue. Intervertebral disc disease, spinal tumours, fibrocartilaginous embolism, and infectious or inflammatory myelitis can all present with varying degrees of hind limb dysfunction. The onset may be acute or progressive depending on the specific condition, and the degree of sensory and motor loss can vary from subtle weakness to complete paralysis with loss of deep pain perception.
Traumatic
Injuries to the spine, pelvis, or hind limbs from falls, vehicular trauma, or other physical impacts can produce acute hind leg paralysis. Spinal fractures or luxations may directly damage the spinal cord, while pelvic fractures may affect the nerves supplying the hind limbs. The history of trauma is not always known, particularly in outdoor cats, and the full extent of injuries may not be immediately apparent from external examination.
Peripheral Neuropathy
Conditions affecting the peripheral nerves supplying the hind limbs can produce weakness progressing to paralysis. Diabetic neuropathy is a recognised cause of hind limb weakness in cats, often producing a characteristic plantigrade stance where the cat walks on its hocks rather than its toes. Other neuropathies, whether metabolic, toxic, or immune-mediated, can similarly affect hind limb function, though the onset is typically more gradual than vascular or traumatic causes.
Neoplastic
Tumours affecting the spinal cord, spinal canal, or the nerves supplying the hind limbs can produce progressive hind leg dysfunction. Lymphoma is the most commonly reported spinal tumour in cats and may produce a gradual onset of weakness that progresses to paralysis over days to weeks. The progression tends to be steady or stepwise, and the paralysis may initially affect one limb before involving both.
Why timing matters
Early observation
The onset characteristics of hind leg paralysis carry significant diagnostic meaning. A sudden, acute onset — where a cat that was walking normally moments ago is suddenly unable to use its hind legs and appears distressed — presents a different picture from a gradual onset over days or weeks. Acute presentations are more commonly associated with vascular events or acute spinal cord injury, while gradual onset may suggest progressive conditions such as tumours, chronic disc disease, or metabolic neuropathies. In the earliest moments, observing whether the cat has any voluntary movement, whether it appears to feel sensation in the hind limbs, and whether the limbs feel warm or cold can provide immediately relevant context.
Later presentation
As time passes following the onset of hind leg paralysis, changes in the cat's condition — whether improving, stable, or deteriorating — provide important prognostic context. Some causes may show gradual improvement as swelling resolves or collateral circulation develops, while others may show progressive worsening as the underlying condition advances. Secondary complications including pressure sores from immobility, urinary retention or incontinence, and muscle atrophy may develop over days to weeks. The cat's overall demeanour, appetite, and engagement with its environment during this period can also reflect the degree of pain and systemic impact.
The trajectory following hind leg paralysis varies dramatically with the underlying cause. Thromboembolic events may show partial improvement over days as collateral circulation develops, though the risk of recurrence remains if the underlying cardiac condition persists. Spinal cord compression from disc disease may fluctuate or progressively worsen without intervention. Neoplastic causes tend to show steady or stepwise decline. Traumatic causes have variable outcomes depending on the severity of neural damage. Whether the paralysis is complete or partial, whether deep pain sensation is preserved, and whether there is any voluntary motor function all influence the expected trajectory.
Conditions commonly associated
When to explore further
Sudden onset hind leg paralysis accompanied by vocalisations of distress, cold or cool hind limbs, and firm or painful calf muscles represents a distinct acute presentation that differs markedly from gradual weakness and carries specific implications regarding the vascular supply to the hind limbs.
When hind leg paralysis develops gradually over days to weeks, starting with subtle incoordination or weakness that progresses to inability to walk, the progressive nature of the onset may suggest a condition that is expanding or worsening rather than a single acute event.
The presence or absence of sensation in the hind limbs — whether the cat reacts to gentle pinching of the toes or skin of the hind legs — provides context about the depth of neural involvement and can help characterise the severity of the underlying process affecting nerve or spinal cord function.
Hind leg paralysis accompanied by loss of bladder or bowel control adds an additional dimension to the presentation, as the nerves controlling these functions travel in close proximity to those supplying the hind limbs, and their involvement may indicate a broader area of neural compromise.
When a previously healthy indoor cat with no known trauma history develops acute hind leg paralysis, the absence of an obvious external cause may direct attention toward internal vascular or neurological processes rather than traumatic injury.
Observing the specific characteristics of the hind leg paralysis — whether both legs are equally affected, whether the limbs feel warm or cold, whether the cat appears to have any sensation when the toes are gently squeezed, and whether there is any voluntary movement however slight — can provide meaningful information about the nature and location of the problem. Noting the exact circumstances and speed of onset, any preceding changes in behaviour or activity, and the cat's overall condition before the event occurred helps build a complete picture of the clinical timeline.
Last reviewed: 24 April 2026 · Dr Alastair Greenway MRCVS