TL;DR: Sudden hind limb weakness or paralysis in cats is a life-threatening emergency that requires immediate veterinary intervention to address potential blood clots or neurological damage.
What does it mean if my cat has hind limb weakness or ataxia?
Hind limb weakness, or ataxia, occurs when a cat loses the ability to coordinate their back legs or lacks the strength to support their weight. This is a symptom of an underlying issue affecting the nervous system, cardiovascular system, or muscles, characterized by:
- Swaying or crossing the legs while walking
- Dragging the back paws
- Inability to jump or support their own weight
Is sudden weakness in my cat's back legs a medical emergency?
Yes, sudden weakness or paralysis in the back legs is a high-priority veterinary emergency. You should seek care immediately for the following reasons:
- It often indicates a Saddle Thrombus (blood clot) lodging at the base of the legs.
- Symptoms like vocalizing in pain, cold back paws, or extreme distress require urgent stabilization.
- Delaying treatment can lead to permanent damage or life-threatening complications.
How does a photo or video help the veterinarian triage my cat?
Providing your veterinarian with a short video of your cat attempting to move is vital for an accurate assessment because:
- Cats often enter a "fight or flight" state at the clinic which can mask neurological symptoms.
- A video of behavior in a natural environment shows the exact nature of the weakness and limb positioning.
- The medical team can evaluate coordination more effectively, leading to a faster diagnosis.
Clinical Context (Merck Veterinary Manual)
Diseases of the spinal column and cord can cause hindlimb weakness or wobbliness in cats and include congenital disorders, degenerative diseases, inflammatory and infectious diseases, neoplasia, nutritional diseases, trauma, toxic disorders, and vascular diseases. Cervical spondylomyelopathy, also known as wobbler syndrome, involves spinal cord compression due to abnormal cervical vertebrae development and can be influenced by genetic factors and possibly nutrition. Arterial thromboembolism, often secondary to conditions causing left atrial enlargement such as cardiomyopathies, hyperthyroidism, or congenital heart disease, can also lead to hindlimb paresis or paralysis, pain, reduced or absent femoral or pedal pulses, and cool, swollen gastrocnemius muscles; however, the tail is commonly unaffected, and the cat can often move the legs above the stifles. Diagnosis of arterial thromboembolism is based on clinical signs, physical examination, and Doppler blood flow readings of the hindlimbs; ultrasound can also identify the thromboembolus.
Chapter: Cardiology, Neurology, Degenerative Disease
Source: The Merck Veterinary Manual, 11th Edition (Page 1245)