TL;DR: Sudden hind leg paralysis is a critical medical emergency that requires immediate veterinary intervention to prevent permanent nerve damage. Seek care at an emergency clinic immediately, as the first 24 hours are the most vital window for recovery.
What is sudden hind leg paralysis and what does it look like in dogs?
Sudden inability to stand on the hind legs, also known as acute paraparesis or paraplegia, occurs when a dog loses the functional use of their rear limbs. This condition often stems from a neurological issue where the communication between the brain and the legs is interrupted, commonly due to spinal cord compression or injury. It can manifest as dragging the back legs, 'knuckling' over on paws, or complete immobility.
Is sudden hind leg paralysis in my dog a medical emergency?
- Urgency Level: High. This is a critical medical emergency that requires immediate action.
- Seek veterinary care at an emergency clinic immediately if your dog loses the use of their back legs.
- Rapid intervention is necessary for conditions like Intervertebral Disc Disease (IVDD) or a Fibrocartilaginous Embolism (FCE) to prevent permanent paralysis.
- The first 24 hours are the most critical for positive recovery outcomes.
How can taking a video of my dog's movement help the veterinarian?
- While safe transport is your priority, a brief 10-second video of your dog’s movement can be a vital diagnostic tool.
- Visual evidence allows the vet to see the exact onset of symptoms and specific neurological "deficits" like "drunk-walking."
- Videos help the veterinary team locate where the spinal issue is occurring before they even begin a physical exam.
Clinical Context (Merck Veterinary Manual)
Sudden inability to stand on the hind legs in dogs can be caused by arterial thromboembolism, often secondary to myocardial disease or underlying disorders such as hyperadrenocorticism, hypothyroidism, renal disease, cancer, and heart disease; occlusion commonly occurs at the distal aortic trifurcation, leading to acute, painful paraparesis and an inability to flex or extend the hock, with decreased sensation distal to the hock and weak or absent femoral pulses. Acute flaccid tetraparesis or tetraplegia can develop within 1-2 days, potentially progressing to facial and laryngeal weakness, and even death from respiratory paralysis, associated with raccoon saliva exposure, where spinal cord reflexes are weak to absent, muscle atrophy is evident within 10-14 days, pain perception remains intact, and CSF analysis shows increased protein with a normal cell count. Spinal trauma can also cause acute signs, potentially progressing with unstable fractures or luxations, and severe thoracolumbar spinal cord injury may cause paraplegia with increased extensor tone in the thoracic limbs; radiographs may reveal vertebral fractures and luxations, but advanced imaging is indicated in animals with suspected spinal trauma and normal radiographs.
Chapter: Cardiology, Neurology
Source: The Merck Veterinary Manual, 11th Edition (Page 1245)