TL;DR: Sudden hind leg paralysis is a critical medical emergency that requires immediate veterinary intervention to maximize the chances of recovery. If your dog cannot use their back legs, seek emergency care immediately and record a brief video of their movement to assist the triage team.
What are the causes and signs of sudden hind leg paralysis in dogs?
Sudden onset of dragging the hind legs, medically referred to as paraparesis or paraplegia, occurs when there is a critical interruption in the communication between the spinal cord and the back limbs. This can be caused by a ruptured disc (IVDD), a spinal stroke (FCE), or acute trauma. It is often accompanied by pain, distress, or a 'knuckling' gait where the dog walks on the tops of their paws.
Is sudden hind leg paralysis in my dog a medical emergency?
- Yes, this is a high-priority emergency, and your dog must be seen by a veterinarian or an emergency animal hospital immediately.
- Rapid intervention is the most significant factor in determining whether a dog will regain the ability to walk.
- Loss of deep pain sensation is a surgical emergency where every hour counts toward a successful outcome.
How does providing a video of my dog help the veterinary triage team?
- Capturing a brief video of your dog attempting to move provides a vital record of their neurological status at the time of onset.
- A video allows the vet to assess the severity of the motor deficit, which may change by the time you reach the clinic.
- Providing visual evidence allows the triage team to prioritize your pet's care the moment you arrive.
Clinical Context (Merck Veterinary Manual)
Sudden onset of dragging hind legs in dogs can be caused by fibrocartilaginous embolism, typically seen in adult, large, and giant breeds, as well as Miniature Schnauzers and Shetland Sheepdogs, presenting with an abrupt onset of gait dysfunction, often during activity, resulting in a focal, asymmetric lesion in the spinal cord, with spinal pain typically absent. Arterial thromboembolism secondary to myocardial disease, or underlying disorders such as hyperadrenocorticism, hypothyroidism, renal disease, cancer, and heart disease, can also cause acute, painful paraparesis with an inability to flex or extend the hock, decreased sensation distal to the hock, and weak or absent femoral pulses. MRI may reveal focal T2 hyperintensity within the spinal cord, and CSF may have a mild increase in neutrophils and protein concentration in the acute stage.
Chapter: Cardiology, Neurology
Source: The Merck Veterinary Manual, 11th Edition (Page 1245)