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Arteriovenous Fistulas in Cats: Causes Symptoms and New Treatment Options

Arteriovenous Fistula in Cats: Causes and Symptoms

If your furry friend is experiencing some unusual symptoms, such as warm and swollen limbs, lameness, or ulcers that are not painful, it is crucial to take them to the vet for a thorough examination. These could be the signs of a health condition called arteriovenous fistula (AVF).

While AVFs are not common in cats, they can occur as a result of trauma or surgery. Let’s delve into the causes of AVFs, its symptoms, and the diagnosis methods used.

An arteriovenous fistula is a low resistance connection between an artery and a vein that bypasses the capillary bed (small blood vessels that connect arteries to veins) and results in a shunting of blood. This condition can be caused by a traumatic injury, arterial puncture, or iatrogenic penetration from surgery.

However, it can also develop spontaneously due to a congenital defect. An AVF can have some severe implications, such as increasing cardiac output, which can lead to congestive heart failure as more blood is pumped through the heart at a quicker rate than usual.

The symptoms of arteriovenous fistula are location-dependent, as the positioning of the AVF can affect how the blood is shunted and which organs will be affected. When the AVF is in the extremities, a cat may experience limb swelling, increased warmth, and the development of ulcers that don’t cause pain.

They may also experience lameness due to the altered blood flow. When the AVF is closer to the heart, the cat may experience congestive heart failure symptoms such as a cough, difficulty breathing, an increased heart rate, and exercise intolerance.

An AVF that results in blood shunting to organs can have a range of symptoms, including distention of the abdomen, seizures, weakness, or paralysis. Diagnosis of AVF can be made through a thorough history and physical exam, where the vet will take into account your cat’s health history and the onset and nature of the symptoms.

The vet will also physically examine the cat to determine the location of the AVF. Biochemistry profiles, urinalysis, complete blood counts, and electrolyte panels are run to examine organ function and detect abnormal levels of any element.

In addition, imaging techniques like thoracic x-rays, Doppler ultrasounds, echocardiograms, and angiographies can help in locating the AVF and assessing the severity.

Arteriovenous Fistula Treatments

In most cases, surgery is recommended to divide and remove the abnormal connections created through the AVF while the cat is under general anesthesia. This surgical procedure can be complex, depending on the location of the AVF and how it has affected the cat’s organs and extremities.

Blood transfusions may also be necessary during the surgical procedure. In some cases, treatment may involve transcatheter embolization, a minimally invasive procedure that involves inserting a catheter into the affected artery to block off the blood vessels that are being shunted.

Living and Management

After surgery, it’s crucial to monitor your cat closely and attend regular follow-up appointments. This allows for evaluation of the cat’s condition and detection of any signs of AVF recurrence.

A recurrence of AVF can be life-threatening, so regular medical attention is crucial for your cat’s overall health and well-being. In addition, as AVFs can sometimes create a high flow of blood to a particular extremity, monitoring and appropriate anti-inflammatory treatments are needed to prevent additional cases of ulceration in the affected area.

Complications of Arteriovenous Fistulae

The primary concern with an AVF is the potential for an increase in cardiac output, which is the amount of blood being pumped through the heart at any one time. Usually, the body only requires a small amount of blood at any given time, and so blood flow is slowed as it passes through the capillary bed, which helps to add oxygen to the blood for healthy cell functions.

When the blood is shunted through an AVF, it can be bypassing vital organs and tissues, not allowing them the chance to process the correct amount of oxygen. This will increase the frequency of heartbeats as well as the blood that is pumped around the body at once, leading to congestive heart failure.


Arteriovenous fistula is an uncommon condition in cats. In some cases, AVF may be the result of trauma or surgical procedures, whereas others may be due to congenital defects.

The symptoms of AVF are location-dependent, and diagnosis can be made through a range of biochemistry and imaging test methods. Treatment for AVF often involves surgical procedures, while recovery management usually involves regular follow-up appointments to monitor for the recurrence of AVF.

With diligent medical attention and monitoring, cats with AVF can live with minimum discomfort and enjoy an elevated quality of life. Causes of Arteriovenous Fistulae: Traumatic Damage, Injections and Surgeries

Although arteriovenous fistulae (AVFs) are rare in cats, there are certain causes that are more common and, therefore, essential to recognize.

In some cases, there may be an underlying congenital defect causing it, however, more commonly, traumatic damage or complications from surgery may lead to the development of an AVF. Damage or trauma to the blood vessels in cats can cause them to rupture, leading to the formation of an AVF.

This could happen from a fall, collision with a vehicle or any other incident that channels significant pressure on the anatomy of the cat, leading to damage to the blood vessels. This damage could affect any area, such as the limbs, face, neck, abdomen or thorax, depending on the nature of the trauma.

Some surgical procedures may also lead to the formation of an AVF if things go awry. Reasonably common surgeries such as the placement of a catheter or the insertion of an arteriovenous shunt for kidney dialysis can lead to this condition.

These complications arise due to the invasive nature of the surgical procedure, which can lead to damage to the blood vessels. Injections or other invasive procedures can also lead to complications that could lead to AVF.

For example, barbiturates injections, which are often used for anesthesia, might cause ruptures in blood vessels, leading to the formation of AVF. Cancerous tumors that exert a significant amount of pressure on the blood vessels located in a specific region can also cause the formation of AVFs in cats.

Surgery Complications and Prognosis

The surgical removal or repair of an AVF can be labor-intensive, complex, and involve significant surgical risks. This is mainly because of the difficult-to-locate instances of an AVF and the complexity of the surgery required to remove it.

Because AVFs present slightly differently in every case, they may require a wide range of procedures based on the location and severity of the AVF’s impact on the cat. As such, removing or repairing an AVF can also be expensive depending on the specific nature of the ailment, and therefore addressing any recurrence risk is crucial.

After surgery, post-surgery follow-up is essential, so a recurrence of AVF is detected early enough and treated immediately. Although the success rate of the surgical procedure has been successful in the past, recurrence can happen, and the probability-heightened in primary cases, and if the procedure was not successful.

When a recurrence of AVF happens in a cat, amputation may sometimes be the most plausible option, as the affected limb may be too far gone to re-operate or repair. In general, the prognosis for cats with AVF is sound, but post-surgery management is crucial because monitoring recurrence and early detection certainly lead to a better standard of living for the cat.

In conclusion, Traumatic damage, injections or surgeries are the primary causes of AVF in cats. Awareness of the likelihood of trauma may allow pet parents to provide a safe space for the cat, reducing the chances of experiencing these kinds of injuries.

When a cat has to undergo a surgical procedure or medical treatment, a thorough understanding of the risks and potential side effects of the treatment plan is essential. AVF is not something to take lightly.

However, with proper care, management, and dedication for the cat’s care and well-being, AVF, like any other ailment, can be treated appropriately. New Treatment Option: Transcatheter Embolization

Traditional surgical procedures are invasive, complicated, and carry a high risk of significant side effects and complications, including recurrence.

Although surgical procedures remain an option for the treatment of arteriovenous fistulae (AVF), new technologies have emerged to treat AVFs in cats, and transcatheter embolization is one of the treatment options. Transcatheter embolization is considered a non-invasive treatment procedure that works remotely to remove an AVF without surgery.

This procedure involves the use of a catheter to access the affected blood vessel, from a minimal incision, and to block off the shunted blood vessels with specific embolic materials. This treatment has gained popularity due to its success rate, which minimizes surgical trauma and the risk of post-operative complications.

This innovative new treatment is particularly useful when surgically removing the AVF is not feasible or the AVF is located in a place that is inaccessible through surgical incisions or procedures. The use of transcatheter embolization is also useful when the AVF is a small or remote lesion, where surgery would be overkill.

Ultimately, the aim of transcatheter embolization is to block off the affected blood vessels to stop the blood shunting process and begin healing the tissues. The materials used in this procedure are defined and specifically selected for each patient, and the treatment is generally well-tolerated by cats who have undergone it.

Overall, the process of transcatheter embolization is less painful than surgical treatment, given the limited incisions required, the shorter length of hospital stay needed post-treatment, the lesser medication requirement, and the minimal duration of the recovery period. However, there are still cases where surgery is necessary, and cat owners should rely on professional veterinary advice to determine the best treatment options for the particular case of their cat.



Arteriovenous fistulae (AVF) is a rare but complex medical condition in cats, marring both their physiological and overall standard of living. Whether caused by a surgical complication, traumatic injury, or tumor, diagnosis of this ailment can be challenging.

AVF can be treated with a combination of measures including surgery, transcatheter embolization, and anti-inflammatory medication for the affected regions. All treatments come with their unique potential for complications that can emerge, and cat owners should be well-informed of this before proceeding with treatment.

The diagnosis of AVF is achieved through a physical examination, biochemistry profile, urinalysis, and imaging techniques like thoracic x-rays, Doppler ultrasounds, echocardiograms, and angiographies. Once diagnosed, the treatment of AVF is dependent on its location, size, and severity.

In some cases, surgery may be the only option, as it remains the most plausible and often reliable treatment option. The surgery has a favorable rate of effectiveness, despite being labor-intensive and expensive, and with the right post-op management and follow-up, cats can enjoy a better quality of life.

However, the management of AVF continues to evolve, and transcatheter embolization is a non-invasive treatment option for certain cases that present themselves. It is important to note that transcatheter embolization may not be suitable for all cases of AVF and the potential risk of complications.

Nonetheless, cat owners should remain optimistic in the management of AVF in their furry friend. Careful monitoring, regular evaluation, and consultation with qualified veterinarians are necessary, as well as sticking to proper medication dose and schedule, monitoring feeding and exercising regimen, and attending regular vet appointments.

With proper care, an early diagnosis, and implementation of the correct treatment regimen, cats with AVF may live healthy, happy, and fulfilling lives. Arteriovenous fistula (AVF) is a rare but complex medical condition in cats, one that can compromise the overall standard of living for a cat.

Trauma, injections, and complications from surgeries are the primary causes of AVF formation in cats. Detection of AVF requires a thorough examination and assessment of the symptoms through imaging techniques such as thoracic x-rays, Doppler ultrasound, and angiography.

Treatment options for AVF include traditional surgical procedures, which remain the most common option, and transcatheter embolization, which is a non-invasive treatment option for small and remote lesions. However, surgery may remain necessary in certain circumstances.

Strict post-treatment management and evaluation are vital in ensuring an effective recovery and preventing recurrence. With proper care and support, cats with AVF can enjoy a healthy and fulfilling life.

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