Saddle Thrombus in Cats: Treatment Options, Palliative Care, and How to Know When It’s Time for Euthanasia

Saddle thrombus, also known as aortic thromboembolism (ATE), is a sudden and devastating condition that affects cats. It occurs when a blood clot travels from the heart and lodges in the lower part of the aorta, the main artery that supplies blood to the hind limbs. This blocks blood flow, leading to sudden paralysis, severe pain, and distress.

Saddle thrombus is a medical emergency. The most common symptom is sudden paralysis and extreme pain. Cats are often meowing or yowling loudly. If your cat has just been diagnosed with saddle thrombus you may find yourself overwhelmed and having to make very serious decisions very quickly.

As a hospice and palliative care doctor practicing in New York City, my goal is always this: regardless of the path you choose, to make sure your cat’s remaining time here on Earth is full of love and happiness. If your options are confusing or you aren’t sure how to know when it’s time for euthanasia, don’t hesitate to schedule a quality of life teleconsult with one of our doctors.

What Is Saddle Thrombus and Why Does It Happen

A saddle thrombus is a blood clot that forms in the heart and travels down the aorta until it becomes lodged and blocks blood flow to both back legs, leading to sudden paralysis and extreme pain.

Most cases are due to undiagnosed heart disease – most commonly hypertrophic cardiomyopathy, which causes the heart muscle to thicken and predisposes cats to clot formation. Cats with saddle thrombus often had no symptoms prior to it occurring.

Treatment Options for Saddle Thrombus

As an emergency veterinarian, saddle thrombus was one of my least favorite conditions to diagnose. Cats would come in screaming in pain. And these cats were often young and – prior to the saddle thrombus – seemingly in perfect health.

Not only that, but most cats do not survive. Even when the most aggressive treatment is pursued (hospitalization, anti-clotting medications), fewer than 50% of cats make it out of the hospital alive, and fewer than 20% are alive a year later.

Because of the extreme pain and these dire statistics, we often recommend euthanasia immediately, rather than putting them through aggressive treatment.

That said, there are some cases where it is reasonable to try to hospitalize and treat a cat with a saddle thrombus. Below is some information about treatment that may help you make the most informed and compassionate decision for your cat.

🩺 Hospitalization and Aggressive Medical Treatment

Treatment for saddle thrombus involves hospitalization (typically for several days), anticoagulant therapy (to try to dissolve the clot), oxygen support, and testing such as echocardiogram to assess for underlying heart disease. Not all cats are good candidates for aggressive treatment. Below are some pros and cons.

Pros:

• Gives cats the best chance of partial or full recovery
• Provides some pain control in the form of injectable narcotics
• If there is no underlying heart disease, they may go on to live a long life (this is relatively rare)

In most cases, the only alternative to euthanasia

Cons:

• Less than 50% of cats hospitalized for saddle thrombus survive to discharge
• Can be costly, often $5000-$10,000.
• Risk of recurrence is high

Best suited for:

• Cats with only one limb affected: this often means the thrombus is smaller and the cat is more likely to regain function of leg
• Cats who are not in heart failure: the ER doctor can often take an x-ray or do a brief ultrasound which might show heart failure or a severely enlarged heart. If your cat has signs of heart failure or a severely enlarged heart, treatment is less likely to be successful and euthanasia might be the kindest option
• Families who are prepared for both short- and long-term ongoing care

Not ideal for:

• Cats with bilateral paralysis and cold extremities (meaning the clot is very big cutting off circulation completely). These cats are less likely to recover.
• Cats with severe underlying heart disease (heart failure or severe heart enlargement)
• Pet parents who cannot commit to ongoing follow up care and daily medications
• Cats who are unresponsive, hypothermic, or in shock

💊 Conservative Medical Management / Palliative Care at Home

I almost never recommend this. These cats are in such extreme pain they need strong narcotic pain medications we can only give in the hospital. There is a select group of patients that may have a very mild thrombus and don’t seem to have significant underlying heart disease. It involves giving your cat oral pain medications (buprenorphine, gabapentin) and anticoagulants (e.g. clopidogrel).

Pros:

• Less costly
• Can be done at home
• May allow some cats to regain function slowly

Cons:

• In most cats, pain cannot be adequately managed
• Does not provide oxygen support if patient needs it
• Must be able to provide round-the-clock monitoring
• Mobility issues may lead to pressure sores or urinary complications

Best suited for:

• Really only recommended in cats who are eating, alert, and only mildly affected and hospitalization not financially feasible
• Family must be committed to intensive care

Not ideal for:

• Cats who are severely painful or immobile
• Cats who are not eating or drinking
• Cats with severe heart disease especially if they need oxygen
• Families that cannot commit to intensive care at home

Emergency euthanasia

Unfortunately, saddle thrombus is a condition where I often do recommend emergency euthanasia. Most cat owners do not want to have to euthanize their cat in the emergency room, but saddle thrombus is a disease where this is often the kindest option.

This is because (1) except in milder cases, they usually do not survive even the most aggressive treatment, (2) they are in such extreme pain it can be hard to control even with potent narcotics.

Although in most cases, I think home euthanasia is kindest for cats, for this disease I do not recommend taking a cat home that is in such extreme pain and waiting for a home euthanasia appointment. Giving them peace as soon as possible is often the kindest option.

My cat survived after a saddle thrombus but I’m worried it will happen again – how do I know when it’s time for Euthanasia?

If you are one of the lucky pet parents whose cat recovered from a saddle thrombus, you may find yourself facing the decision for euthanasia again in the near future.

I strongly recommend making a comprehensive end-of-life care plan early, especially if your cat has been diagnosed with heart disease (heart failure or hypertrophic cardiomyopathy).

A comprehensive end-of-life-care plan is similar to an advanced directive in humans. It involves answering questions about what treatments you would and would not pursue, how aggressive you would get with medical care, and developing objective criteria for euthanasia.

It is much easier to make these decisions when you are in a relatively calm frame of mind. When we are facing an immediate crisis of possibly losing our pets, it’s easy to make the wrong decisions in a panic. I’ve made this mistake myself.

💭 Questions to Ask Yourself:

• Am I able to administer medications several times a day?
• Can I monitor my cat’s pain and comfort effectively at home?
• Would I pursue hospitalization again if a recurrence happens?
• Do I have a plan in case of another emergency?
• Do I want to ensure my cat has a home euthanasia rather than risk an emergency hospital visit?
• What are some criteria for euthanasia to choose so my cat does not suffer at the end?
• Is everyone in my family comfortable with this plan?

📋 Objective Criteria for Euthanasia in cats with saddle thrombus

• Recurring saddle thrombus or other blood clots – personally, I would elect euthanasia if a clot recurred, due to how painful the condition is and how stressful the treatment
• Difficulty breathing: if your cat has underlying heart failure that is no longer responding to medications, it is time to consider euthanasia
• Other signs of advanced heart failure: such as a distended belly that is causing loss of appetite or discomfort and is no longer responding to treatment
• Lack of enjoyment in life: If your cat is isolating frequently, not engaging with their favorite people, or is generally lethargic and no longer seems to be enjoying life, it may be time to consider euthanasia
• Persistent loss of appetite or signs of systemic decline (vomiting, dehydration)

📓 Daily Journaling Can Help

Use a simple journal to track your cat’s quality of life. Each day, record:

A 😊 for a good day
A 😞 for a bad day

You can also use this space to write down meaningful memories or small joys. Over time, the pattern can help guide your decision and provide peace of mind.

Our Quality of Life Scale (https://pawsatpeace.com/quality-of-life-scale/) is another helpful tool to help you assess your cat’s quality of life. This quiz can be taken once to give you a snapshot or taken multiple times to assess trends over time.

The hardest part of saying goodbye is often the timing. Waiting for a crisis can mean an emergency, rushed trip to the ER, and a more traumatic end for both of you. When your cat is starting to have more bad days than good ones, that’s often the time to plan a peaceful sendoff.

Final Thoughts

Saddle thrombus is one of the most heartbreaking diagnoses a cat can receive. It’s sudden, painful, and complicated. There are no easy answers, but your decisions—whatever they are—come from love.

Whether you pursue treatment, provide palliative care, or choose to say goodbye, our role is to help you honor your cat’s life with compassion and dignity.

If you’re unsure what to do next, consider scheduling a teleconsult with one of our compassionate veterinarians. We can review your cat’s medical records, talk through your options, and help you plan the most peaceful and loving path forward.

And when the time comes, Paws at Peace offers in-home euthanasia, so your cat can pass gently, surrounded by family, in the comfort of home.