Vet’s 2025 Guide to Aortic Thromboembolism in Dogs – Causes, Diagnosis & Care 🐾

By Dr. Duncan Houston BVSc

💡 What Is Aortic Thromboembolism?

Aortic thromboembolism (also called saddle thrombus) occurs when a blood clot (thrombus or embolus) lodges at the terminal aorta—often at the bifurcation supplying the hind limbs—causing severe blood-flow blockage to pelvic limbs and possibly other organs. Rare in dogs compared to cats, but often extremely painful and serious.

⚠️ Who’s at Risk & Why?

• Underlying diseases: hyperadrenocorticism (Cushing’s), diabetes mellitus, hypothyroidism, protein‑losing nephropathy/enteropathy, heart disease (endocarditis, cardiomyopathy), sepsis, neoplasia, immune‑mediated disorders, pancreatitis, parasitism, trauma.
• Breed predisposition: Greyhounds, Soft‑Coated Wheaten Terriers, Cavalier King Charles Spaniels, Miniature Schnauzers.
• Age & sex: most common in middle‑aged to older dogs; males slightly more affected.

🎯 Clinical Signs

• Acute: sudden hind-limb paralysis or weakness, severe pain, vocalization, cold pale limbs, absent femoral pulses, hypothermia.
• Chronic: exercise intolerance, lameness, muscle wasting, variable pulses.
• Optional: abdominal pain, vomiting, collapse, respiratory distress from concurrent disease.

🔬 Diagnostics

• Physical exam: check femoral pulses, limb temperature, tone, and abdominal pain.
• Blood work: CBC, chemistry (e.g., CK, AST), urinalysis (UPC), clotting tests (PT/aPTT, D-dimer, fibrinogen).
• Ultrasound & Doppler: visualize thrombus at the aortic bifurcation with absent blood flow in iliac vessels. Images above show Doppler and CT angiography of aortic thrombus.
• X-rays/CT/MRI: help assess thrombus, underlying pathology, organ involvement.

💊 Treatment & Urgent Care

• Hospitalization: pain relief, oxygen, intravenous fluids, temperature stabilization.
• Thrombolytics: e.g., streptokinase in early cases; high complication risk (reperfusion injury).
• Anticoagulants & antiplatelets: heparin, aspirin, clopidogrel, possibly warfarin—with careful monitoring.
• Surgery or thrombectomy: mechanical or surgical removal in select cases – some success reported.
• Treatment of underlying cause: e.g., endocrine disease, infection, neoplasia, etc. to prevent recurrence.

🏡 Prognosis & Follow‑Up

• Prognosis is guarded: median survival spans days to several months; a minority live longer.
• Chronic cases may stabilize with consistent management of disease and clot prevention.
• Regular follow-up: recheck limb pulses, imaging of thrombus resolution, blood work, and underlying disease monitoring every 1–3 months.

🛡️ Prevention & Risk Reduction

• Screen and manage risk factors—PCV, endocrine diseases, and protein loss conditions.
• Consider prophylactic antithrombotics in high-risk dogs (with vet guidance).
• Routine wellness exams with pulse palpation and basic clotting evaluations in predisposed breeds.

📲 Owner Resources & Support Tools

• Ask A Vet: Telehealth helps for urgent management, treatment planning, and follow-up care.

🌟 Case Snapshot

Case: “Jack,” a 13‑year‑old Jack Russell with new-onset hind limb dragging and absent pulses in one leg, was diagnosed via ultrasound with a saddle thrombus secondary to newly diagnosed diabetes. Treated with hospitalization, pain control, heparin, clopidogrel, and managed endocrine disease. At 3‑month follow-up, pulses returned, thrombus reduced on ultrasound, and Jack remains walking on all four paws. 🐾

✅ Key Takeaways

• Aortic thromboembolism in dogs is rare but often serious, presenting with sudden limb paralysis, pain, and pulse loss.
• Emergency diagnosis includes physical exam, imaging, Doppler ultrasound, and lab work.
• Treatment combines pain relief, clot dissolution, anticoagulation, and sometimes surgery, but recurrence is common.
• Prognosis is guarded—long-term survival depends on underlying disease control and early intervention.
• Ask A Vet and supportive tools can significantly aid in acute management and long-term wellness 🩺🐶

📥 Need Emergency Help?

If your dog suddenly can't use its back legs or is in pain, seek immediate vet care. For real-time vet support and guidance on treatment options, download the Ask A Vet app or visit AskAVet.com. We're here 24/7 to help. 🐾