Aortic Thromboembolism in Cats: Causes, Signs and Care

Aortic thromboembolism (ATE) in cats is a serious complication of heart disease, especially in breeds prone to cardiac issues. This painful condition occurs when a blood clot forms in the heart, travels down the aorta, and blocks blood flow to the hind legs or other vital organs, causing sudden paralysis and severe pain in affected limbs.

For cat owners aware of their pet’s heart condition, understanding the signs of aortic thromboembolism and seeking immediate veterinary care can be critical to your cat’s well-being and quality of life.

What causes aortic thromboembolism in cats?

Aortic thromboembolism most often results from underlying heart disease, particularly hypertrophic cardiomyopathy (HCM), which affects the heart's structure and function, increasing the risk of clot formation. Three key factors contribute to ATE development:

• Damage to the lining of the heart (endothelium)
• Increased clotting tendency in the blood
• Pooling or stasis of blood within the heart chambers

Other less common causes include systemic illnesses such as kidney disease, bacterial infections of the heart lining (bacterial endocarditis), Cushing’s disease, and liver disorders, all of which can predispose to clot formation.

Recognising the signs of aortic thromboembolism in your cat

The hallmark of ATE is the sudden onset of hind limb paralysis or severe weakness, accompanied by obvious pain. Your cat may vocalise distress and appear reluctant or unable to move the affected legs.

Additional signs include coldness and paleness of the paws on affected limbs, laboured or rapid breathing due to cardiovascular stress, and loss of bladder or bowel control in severe cases. These symptoms may mimic trauma from injuries such as road accidents, so swift veterinary diagnosis is imperative.

Diagnosing aortic thromboembolism

Your vet will assess your cat’s medical history, especially any known heart disease, and perform a thorough physical examination. Key clinical signs include:

• Absent or weak femoral pulses in the hind legs
• Cold, pale, or cyanotic paw pads on affected limbs
• Paralysis or marked weakness of the hind limbs
• Stiffness and signs of pain on limb manipulation
• Heart murmur detected during auscultation
• Abdominal tenderness if embolism involves other organs

Diagnostic imaging such as echocardiography confirms underlying heart disease and may detect blood clots. Blood tests help evaluate overall health and clotting status.

Treatment options and prognosis

Unfortunately, treatment of aortic thromboembolism is challenging and often unsuccessful. Many cats require euthanasia due to the severe pain and poor likelihood of full recovery. Treatment decisions depend on factors such as the severity of paralysis, extent of clotting, and heart function.

When treatment is attempted, initial steps focus on stabilising the cat's condition and controlling pain with strong analgesics. Surgical removal of the clot may be attempted but is rarely feasible. Medication to dissolve clots (thrombolytics) is used cautiously because of bleeding risks.

More commonly, supportive care includes anticoagulants like heparin to prevent new clots, vasodilators to improve blood flow, and intensive nursing to manage limb function and pain. Recovery is slow and only partial restoration of mobility is common, with a high chance of recurrence.

Preventing aortic thromboembolism

Preventing ATE in cats with heart disease is challenging as clot formation may occur despite anticoagulant therapy. Heparin is often started after a first thrombotic event to reduce recurrence risk, while warfarin use requires careful monitoring due to side effects.

If your cat has a diagnosed heart condition, regular veterinary monitoring and maintaining optimal heart health are crucial. Early detection and management of heart disease, alongside vigilant observation for sudden limb signs, provide the best chance for prompt intervention.

Supporting your cat’s quality of life

While ATE is devastating, understanding this condition empowers you as a responsible cat owner to act swiftly and support your feline companion through advice from your vet. Providing a calm, comfortable environment and adhering to prescribed treatments can help maintain quality of life for cats living with heart disease.

Remember, if you notice sudden hind limb weakness or paralysis in your cat, seek immediate veterinary assistance for timely diagnosis and care. Early action could make a significant difference.