Get

In Your Inbox

Catster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

Blood Clots in Cats (Aortic Thromboembolism) – Vet Answer on Causes, Symptoms & Care

Sick cat in animal hospital

Feline Aortic Thromboembolism (abbreviated FATE) is a highly fatal disease caused by a blood clot becoming stuck at the aortic trifurcation—the area where the blood supply to both back legs occurs. This condition almost always occurs acutely, and can come as quite a shock to owners. FATE can occur when your cat has shown absolutely no other signs of illness prior to the event.

In this article, we will discuss the causes, symptoms and recommended care for cats affected with FATE.

divider single cat paw oct 2024

 

What is an Aortic Thromboembolism?

FATE, otherwise known as a “Saddle Thrombus”, is when a blood clot becomes lodged within a cat’s aortic bifurcation (i.e., the “saddle”). This simple diagram may make it easier to understand where this occurs. The descending aorta travels from the heart, through the chest and abdomen, eventually splitting into two vessels—the iliac arteries, which supply blood to both hind limbs. Cats suffering from FATE will get a blood clot right at this bifurcation.

The blood clot may occur within the middle of this bifurcation, cutting off the blood supply to both back legs. The blood clot may also occur slightly more on one side than the other. If this occurs, your cat may just have the blood supply cut off to one of the hind legs.

Cats can get blood clots in other places in the body. For this article, we will be focusing on the blood clots that lodge at this specific location in the body.

sick cat lying on blanket
Image credit: one photo, Shutterstock

What Are the Signs of an Aortic Thromboembolism?

If your cat suffers from FATE, the signs will be severe, dramatic, and often shocking to witness. Cats may show absolutely no signs of illness before they suffer from FATE. Once the clot occurs, it’s an extremely painful process. Affected cats are often in excruciating pain and will howl, scream, and may try to bite owners when they are typically very affectionate.

Cats will be unable to move and/or feel one or both of their back legs. Owners often find them dragging themselves across the floor, vocalizing, panting, and sometimes having difficulty breathing as well. If your cat will allow you to touch them, you’ll notice that the affected back legs will be cold to the touch, and the paw pads will often appear pale pink or dusky. Lack of a pulses to the affected legs is also present.

Unfortunately, some cats who suffer from FATE may progress to death very quickly. Sadly, some cats may not even make it to their veterinarian once the clot occurs.

Is your cat presenting any of these signs? We suggest you speak with a vet online.

If you need to speak with a vet but can't get to one, head over to PangoVet. It's an online service where you can talk to a vet online and get the advice you need for your pet — all at an affordable price!

PangoVet_Mention-in-Content for PangoVet2 save money

What Are the Causes of Feline Aortic Thromboembolism?

The most common reason why FATE occurs is cardiac, or heart disease. FATE may be the first sign that your cat has heart disease. Depending on the study, anywhere from 12–30% of cats suffering from FATE were diagnosed with cardiac disease.

If the blood clot is caused from heart disease, it’s commonly because the heart has a structural abnormality making it difficult to pump blood normally. In a normal heart, every drop of blood is squeezed out of the heart into the arteries with every beat. However, with some forms of heart disease frequently seen in cats, the heart cannot squeeze normally—often, from the heart muscle being too thick. This will cause small amounts of blood to remain in some of the heart chambers, swirling around creating blood clots. The longer blood remains abnormally in a chamber, the higher the likelihood of developing clots. Once pumped out into the body, these blood clots can then become lodged.

Vet looking for swelling in cat paws
Image Credit: Motortion Films, Shutterstock

If heart disease is not present, there are other diseases that may make blood clots form in the body. If your cat has any type of cancer, this may make them more prone to blood clots. Cats with an overactive thyroid, known as hyperthyroidism, and cats with kidney disease or hypertension may be at increased risk of forming blood clots.

Unfortunately, FATE may occur without any knowledge of your cat being sick. You may have no idea they have heart disease, kidney failure, cancer, or a thyroid problem. Your cat may also just suffer from FATE with no other underlying illness. This diagnosis is referred to as idiopathic.

How Do I Care for a Cat with an Aortic Thromboembolism?

Cats suffering from an aortic thromboembolism need to be seen by a veterinarian immediately. There is absolutely nothing you can provide at home, and no OTC or human products that you should give to help your cat. Cats suffering from FATE are typically very stressed, having difficulty breathing, and very painful. Do not try to offer your cat food, water, or any treatment at home. Get them to your veterinarian or the nearest emergency veterinarian as quickly and safely as possible.

If you suspect your cat has FATE, you should grab a large towel or blanket and gently wrap your cat in it. This will help to protect your hands and arms from your cat if they try to bite, scratch, and get away. You can then put your cat, wrapped in the towel or blanket, into a carrier or an open-topped box. Make sure your cat’s head is exposed so they can breathe as comfortably as possible.

Be aware that it is very typical for cats with FATE to be thrashing, howling, biting, gator rolling, and in general, extremely stressed and freaking out. You need to take precautions to keep both yourself and your cat as safe as possible.

toyger kitten wrapped in a towel
Image Credit: stockelements, Shutterstock

As discussed above, this is an extremely painful condition. Your cat will require strong pain medications, at minimum. Your veterinarian may also need to administer sedatives, oxygen support, and potentially cardiac medications to your cat. Depending on where you take your cat, some clinics (typically universities and specialty clinics) may administer anticoagulant medication. However, these medications are not routinely given, and availability may be limited.

FATE is a highly fatal condition in cats. Even with immediate, aggressive care, many cats do not improve. Some cats will pass away on their own, while others are humanely euthanized due to their severe condition. These possibilities are important to be aware of, should you ever experience this with your cat.

divider single cat paw oct 2024

Frequently Asked Questions (FAQs)

How will my veterinarian diagnose a FATE?

Cats suffering from an aortic thromboembolism will have very typical signs and lead your veterinarian to a presumptive diagnosis. The pain, howling, and inability to use one or both hind legs, in addition to the lack of pulses to the affected hind legs are typically present. If there is an underlying heart condition, your veterinarian may also hear a heart murmur or arrhythmia. Ultrasound with Doppler and other advanced imaging modalities, such as a CT, would be needed for a definitive diagnosis.

veterinarians examining a grey cat
Image Credit: Juice Flair, Shutterstock

Will my cat recover from an aortic thromboembolism?

Unfortunately, many cats are euthanized once suffering from FATE. Once they lose blood flow to their back legs, tissue damage and self-damage may occur. If your cat does improve, keep in mind that the underlying cause of the blood clot is still present.

divider single cat paw oct 2024

Conclusion

Feline aortic thromboembolism, abbreviated FATE, is a severely painful and debilitating condition. These blood clots are frequently associated with underlying heart disease, and FATE may be the first sign that your cat has heart disease. If your cat shows any of the typical signs of FATE, you should get them to a veterinarian immediately. Unfortunately, even with aggressive, immediate care, many cats will not recover.


Featured Image Credit: Kachalkina Veronika, Shutterstock

Want content like this delivered to you?

Sign Up For Our Newsletter

News, insights, expert advice, and everything cat

* By submitting, you agree to our Terms & Conditions and Privacy & Cookies Policy.

How useful was this post?

Click on a star to rate (you can leave written feedback after clicking submit)

Help us improve Catster for pet parents!

Your feedback really matters.

What did you like about this post? Also how can we improve it?

Join the conversation

Leave a Reply

You’re very welcome to leave a comment or question. Please know that all comments must meet our community guidelines, and your email address will NOT be published. Let’s have a positive and constructive conversation.

Talk With A Vet Online

Peace of mind,
anywhere, anytime

Affordable vet advice

Cats & Daylight Savings Time: Will It Affect My Pet? Vet-Approved Facts & Care Tips

Daylight savings time is either a hassle or a gift, and there’s no way around it, as an extra hour tacked on at...

How Do Tabby Cats Get Their Stripes? What Science Tells Us

The tabby cat can differ in appearance, from stripes to spots, whorls, and more. All of these variations have their own names, but...

9 Vet-Reviewed Signs Your Cat Is Bored & How to Fix It

Heaven forbid your cat should be short on entertainment. If they don’t have enough to do, you might notice a few different behaviors...

Do Cats Age Like Dogs? What Science Tells Us

Both cats and dogs age faster than humans. When a cat or dog has only been alive for a few years, they are...

More related

Cuddly Kitten Day 2025: What & When It Is

What could be better than a full day devoted to recognizing the adorable and wonderful traits of kittens? We’re sure that you won’t...

Addison’s Disease in Cats: Our Vet Explains Causes, Signs & Treatments

Addison’s Disease, also known as hypoadrenocorticism, occurs due to a deficiency in adrenal gland hormones. It is a rare condition in cats. The...

Why Does My Cat Lie on Top of My Laptop? 3 Vet-Reviewed Reasons

Any of us who share our lives and homes with a cat knows that they’re the real ruler of the roost. Enjoying a...

How to Deal With Cat Hair in Your Home: 10 Helpful Ways

When you commit to caring for a cat, you also commit to dealing with their stubborn hair in your home. Many cat owners...

Keep reading

Why Do Cats Sneak Around? 10 Possible Reasons for This Behavior

Our favorite furry phantoms are famous for their insane stealth skills that could put a ninja to shame, but have you ever stopped to wonder why exactly they sneak in the first place? You probably know it’s related to their...

A,Timid,Black,Domestic,Shorthair,Cat,Hiding,And,Peeking,Out

How Much Do Cat Vaccines Cost? 2025 Price Guide

One important task that we can do as cat parents is to make vaccinations a priority. An initial round of vaccinations will keep your kitten healthy as they grow into adulthood, but vaccinations should not stop there. There is a...

ginger cat having vaccination

How Do I Get Poison Ivy Off My Cat Safely? 5 Vet Recommendations

Poison ivy can cause serious problems for you and your cat. You can spread the oils that cause the rash to each other, and complications can pop up in humans and felines. Luckily, poison ivy is typically nothing more than...

Poison Ivy Plants

Why Is My Cat Stalking Me? Normal vs Worrisome Behavior

Cats stalk their prey, stalk their toys, and sometimes even stalk their food. However, what concerns many cat owners is when their cats decide to stalk them. You’re probably familiar with the behavior of cat stalking and pouncing. They slowly...

woman sitting beside her cat

10 Best Cat Toothpastes of 2025 – Reviews & Top Picks

Oral hygiene plays a significant role in the overall health of our feline friends. As humans do, cats also need a regular dental hygiene routine to keep their teeth and gums in top condition, prevent tartar buildup, and freshen their...

cat getting teeth brushed

Does Alcohol Kill Fleas on Cats? Vet-Reviewed Effectiveness & Safety Explored

Disclaimer: The information about these products has been fact-checked by one of our licensed veterinarians, but the purpose of this post is not to diagnose illness or prescribe treatment. The views and opinions expressed are not necessarily those of the...

isopropyl alcohol

How Long Do Sphynx Cats Live? Vet Reviewed Lifespan, Care Tips & FAQ

You can’t help but notice a Sphynx cat. The large ears and almond-shaped eyes command your attention. It’s no wonder that they are the 10th most popular breed! Of course, the kitty’s outgoing and energetic personality also helps endear them...

calico sphynx cat on the table

Why Do Cats Like Chin Scratches? 9 Vet-Reviewed Reasons

If you own a cat, you know that cats love chin scratches. You’ve probably noticed that they will rub their cheeks against your hand or any other surface if you give them the chance. That’s because cats have scent glands...

woman scratching cat's chin