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. 🐾