TL;DR: Sudden hind leg paralysis in cats is a life-threatening medical emergency often caused by a blood clot or spinal injury. Seek immediate emergency veterinary care as this condition is extremely painful and requires urgent medical intervention.
What causes sudden hind leg paralysis in my cat?
- Feline Aortic Thromboembolism (FATE): Also known as a "saddle thrombus," this occurs when a blood clot from the heart lodges where arteries branch to the hind limbs.
- Physical Symptoms: Affected legs may feel cold to the touch, and paw pads may appear blue or pale.
- Spinal Issues: Paralysis can also result from sudden spinal cord trauma or severe disc herniation.
Is sudden hind leg paralysis in my cat a medical emergency?
- Immediate Action Required: Take your cat to the nearest emergency veterinary hospital immediately, regardless of the time of day.
- Emergency Status: This is a high-priority, life-threatening emergency that is extremely painful for the animal.
- Do Not Delay: Do not wait to see if the condition improves or wait for a standard appointment; immediate intervention is necessary.
How can a photo or video of my cat’s symptoms help the triage team?
- Provide Vital Information: A quick video of your cat moving or a photo of their resting posture gives the triage team essential data before you arrive.
- Differentiate Conditions: Visual evidence allows staff to quickly distinguish between neurological issues and vascular blockages.
- Accelerate Treatment: This preparation ensures your cat receives the correct life-saving interventions the moment you walk through the door.
Clinical Context (Merck Veterinary Manual)
Arterial thromboembolism, often secondary to conditions causing left atrial enlargement such as cardiomyopathy, hyperthyroidism, or congenital heart disease, is a common cause of sudden hind limb paralysis in cats. Thrombi form in the left atrium and can embolize, most commonly lodging at the aortic trifurcation (saddle thrombus). Clinical signs include pain, paresis or paralysis of the hind limbs, reduced or absent femoral or pedal pulses, cool extremities, and firm, swollen gastrocnemius muscles. The cat may still be able to move the legs above the stifles, and the tail is commonly unaffected. Diagnosis is based on clinical signs, physical examination, and Doppler blood flow assessment of the hind limbs. Ultrasound can also be used to identify the thromboembolus. While spontaneous lysis can occur, numerous treatments have been tried but are largely unsuccessful compared with waiting for the thromboembolus to lyse on its own. Analgesics, nursing care, and treatment of any underlying disease are crucial. Anticoagulants may be used to reduce continued thrombus formation. The prognosis remains guarded, with a high rate of euthanasia or mortality during the initial episode, and potential for permanent neurological deficits.
Chapter: Cardiology
Source: The Merck Veterinary Manual, 11th Edition (Page 1245)