TL;DR: Feline Aortic Thromboembolism (Saddle Thrombus) is a life-threatening medical emergency where a blood clot blocks circulation to the back legs, requiring immediate veterinary intervention for pain management and stabilization.
What is Feline Aortic Thromboembolism (Saddle Thrombus) and how does it affect my cat?
If your cat has suddenly lost the use of their back legs, has cold paw pads, and is vocalizing in extreme distress, they are likely experiencing Feline Aortic Thromboembolism (FATE), commonly known as a Saddle Thrombus. This occurs when a blood clot, often originating from the heart, travels down the aorta and lodges where the artery splits to supply the hind limbs, completely cutting off blood flow.
Is a saddle thrombus a veterinary emergency for my cat?
- The urgency level is High; this is a life-threatening medical emergency and one of the most painful conditions a cat can experience.
- Lack of blood flow leads to rapid tissue death and nerve damage.
- You must take your cat to the nearest 24-hour emergency veterinary hospital immediately.
- Do not wait for an appointment or try to manage the pain at home.
How can a photo help the veterinary team triage my cat's condition?
- While you should not delay transport, capturing a quick photo of your cat's posture or the color of their paw pads (which may appear blue or pale) can be invaluable for the veterinary triage team.
- Showing this photo to the front desk upon arrival allows them to instantly recognize the circulatory crisis.
- This information helps the team prioritize your cat for immediate stabilization and pain management.
Clinical Context (Merck Veterinary Manual)
Arterial thromboembolism, often secondary to conditions causing left atrial enlargement such as cardiomyopathy or hyperthyroidism, can result in acute pain and paresis or paralysis of the hindlimbs. Clinical signs include reduced or absent arterial pulses (femoral or pedal) in the affected limbs, which are cooler than normal, along with firm, swollen gastrocnemius muscles. Diagnosis is based on clinical signs, physical examination, and Doppler blood flow readings of the hindlimbs, with ultrasound useful for identifying the thromboembolus. Management includes analgesics, nursing care, and treatment of any underlying disease. While neurologic deficits may improve over weeks to months, the long-term prognosis is guarded, and euthanasia is common.
Chapter: Cardiology, Emergency
Source: The Merck Veterinary Manual, 11th Edition (Page 127)