TL;DR: Sudden hind limb paralysis in dogs is a high-priority medical emergency that requires immediate veterinary care, ideally within a 12 to 24-hour window to ensure the best chance of recovery.
What causes sudden hind limb paralysis in my dog?
Finding your dog suddenly unable to use their back legs is an incredibly distressing experience. This condition, often referred to as paraplegia, occurs when there is a disruption in the communication between the spinal cord and the hind limbs. Common causes include Intervertebral Disc Disease (IVDD), Fibrocartilaginous Embolism (FCE or 'spinal stroke'), or acute spinal trauma. Regardless of the cause, the loss of motor function indicates a serious neurological event that requires immediate attention.
Is sudden back leg paralysis in my dog considered a veterinary emergency?
- High-Priority Emergency: Sudden paralysis of both back legs is a critical emergency.
- Time-Sensitive Recovery: The window for successful surgical or medical intervention is very short, often only 12 to 24 hours to preserve the best chance of recovery.
- Immediate Action Required: Contact an emergency veterinary hospital immediately if your dog shows severe pain, loss of bladder control, or "knuckling" (dragging the tops of their paws).
How can a photo or video help the vet triage my dog's condition?
- Visual Assessment: Capturing a short video of your dog's movement or a photo of their resting posture allows professionals to assess the severity of neurological deficits.
- Distinguish Symptoms: Visual information helps the veterinary team distinguish between general weakness and true paralysis.
- Clinical Preparation: Providing media in advance allows the hospital to prepare diagnostic tools like MRI or CT scans and prioritize your pet's care the moment you arrive.
Clinical Context (Merck Veterinary Manual)
Sudden back leg paralysis in dogs can stem from several causes. Arterial thromboembolism, often secondary to myocardial disease or underlying disorders such as hyperadrenocorticism, hypothyroidism, renal disease, cancer, or heart disease, can cause acute, painful paraparesis and an inability to flex or extend the hock. Another cause is fibrocartilaginous embolism, where fragments from intervertebral discs occlude spinal cord arteries or veins, leading to an abrupt onset of gait dysfunction, primarily in adult, large-breed dogs. A short-strided gait may also progress to flaccid tetraparesis/tetraplegia. Diagnosis of arterial thromboembolism is based on clinical signs, increased serum CK, and Doppler ultrasonography. Fibrocartilaginous embolism is diagnosed via clinical findings and MRI, which reveals focal T2 hyperintensity in the spinal cord without compression. Prognosis is poor for fibrocartilaginous embolism if deep pain perception is lost.
Chapter: Cardiology, Neurology
Source: The Merck Veterinary Manual, 11th Edition (Page 1245)