Dr. Bashir's Veterinary Practice

A life threatening issue

Aortic Thromboembolism in Cats

What is aortic thromboembolism?
Aortic thromboembolism (ATE) is a devastating condition. The aorta is the main artery of the body and carries oxygenated blood from the heart out to the rest of the body.

The word thromboembolism combines the words thrombus and embolism. A thrombus is a blood clot that occurs inside a blood vessel, and the word embolism indicates that the clot has traveled through a blood vessel to a location distant from where it formed.

An aortic thromboembolism results when a blood clot is dislodged and travels through the aorta, becoming lodged in a distant location. This clot causes severely reduced blood flow to the tissues receiving blood from that section of the aorta, leading to decreased oxygen in the tissues. This condition is also sometimes called a saddle thrombus.

What cats are at risk of aortic thromboembolism?
While aortic thromboembolism is a rare occurrence in dogs, it is much more common in cats. Certain breeds are more commonly affected (mixed breed, Abyssinian, Ragdoll, and Birman), and males are more likely to be diagnosed than females. The age range of affected cats is reported as 1–21 years of age, but most commonly occurs between 8 and 12 years of age.

Affected cats often have underlying heart disease called hypertrophic cardiomyopathy, in which the heart muscle thickens and loses function. The lower heart chambers (ventricles) decrease in size and contracting ability (see handout "Cardiomyopathy in Cats" for further information on this type of heart disease). Blood flow through the heart is compromised, and clots can form that later become dislodged into the aorta.

Aortic thromboembolism can also be associated with cancer or with a body-wide generalized infection called sepsis.

What are the signs of aortic thromboembolism?
The most common clinical signs of aortic thromboembolism are sudden paralysis and pain, usually in the rear legs, although weakness and lameness may be seen.
If the rear limbs are affected, there may be decreased or absent pulses in the femoral arteries of the rear legs. Sometimes, a front leg is involved.
Rapid breathing or difficulty breathing may be seen.
The cat may vocalize from pain and may act anxious.
Occasionally, the cat will vomit.
The nailbeds and foot pads may be pale or bluish.
The cat may experience a lower-than-normal body temperature.
Sometimes, the heart will sound abnormal through a stethoscope, with a murmur or irregular heartbeat being heard.
How is aortic thromboembolism treated?
Unfortunately, the prognosis for a full recovery is guarded to poor. As the condition can be extremely painful, humane euthanasia is a viable option for many cats. If treatment is attempted, most cats need to be hospitalized to manage pain and any concurrent heart disease. They may be anxious and in pain. Supplemental oxygen therapy may be beneficial.

"If treatment is attempted, most cats need to be hospitalized to manage pain and any concurrent heart disease."
Initially, affected legs should be handled minimally. As blood flow returns, physical therapy (passive extension and flexion of the legs) may speed full recovery. Affected cats may need assistance with urinating and defecating. It is best to restrict activity as treatment starts, and the main goal is to keep the cat stress-free. There may be sudden death, usually associated with irregular heartbeats, secondary to increased levels of potassium in the blood. Potassium and other products are released when blood flow returns to oxygen-deprived tissues.

Stressed cats tend not to eat, so it is important to encourage food intake in any way possible. Cats who stop eating suddenly can accumulate fats in the liver, a condition called hepatic lipidosis or fatty liver syndrome. This condition can be fatal.

Surgical removal of the aortic thromboembolism is typically not recommended, as these are high-risk patients due to their severe heart disease.

Aspirin, and a similar drug called clopidogrel (brand name Plavix®), is theoretically beneficial during and after an episode of aortic thromboembolism but should be used only under the direct supervision of your veterinarian. These drugs prevent platelets (blood cells that assist with blood clotting) from activating to clump together and form a clot while flowing through the blood vessels.

Recently, an anti-blood-clotting medication called low molecular weight heparin (LMWH) has been proposed for long-term prevention of aortic thromboembolism in cats. Medications to break up the clot have been tried but must be started right away and should only be attempted at specialized referral centers as rates of complications are high.

Finally, the cat’s heart disease should be treated as appropriate for the type and severity of the disease.

Is any monitoring required? What is the expected outlook?
Blood work, chest X-rays, and cardiac ultrasound should be done routinely to assess the management of heart disease. Blood clotting tests will be performed if anti-clotting medication is used. The cat’s legs will be evaluated to assess the clinical response to therapy. Unfortunately, there is a high rate of recurrence of blood clot formation. There may be permanent nervous system damage, or the hind leg muscles may be adversely affected.

The expected course of this disorder is days to weeks for full recovery of function in the legs, but the prognosis in general is very poor. Long-term survival varies between two months to several years, with the average being a few months with treatment. Most cats that survive the initial episode will be on some type of medication to prevent blood clotting (anticoagulant therapy) and may require frequent re-evaluations and an indoor lifestyle.

© Copyright 2024 LifeLearn Inc. Used and/or modified with permission under license.

Courtney Barnes, BSc, DVM; Malcolm Weir, DVM, MSc, MPH; Robin Downing, DVM, DAAPM, DACVSMR, CVPP, CRPP

Ref: https://vcahospitals.com/know-your-pet/aortic-thromboembolism-in-cats

Case Report: Feline Urinary Capillariosis

Clinic:: DPC Veterinary Hospital
Patient; Paulie, 5-Year-Old Female Spayed Domestic Shorthair
Abstract
Feline urinary capillariosis is a rare parasitic condition affecting the urinary tract of domestic cats. This case report describes a 5-year-old spayed female domestic shorthair, Paulie, who presented with hematuria and dysuria. Diagnostic urinalysis revealed the presence of characteristic operculated eggs consistent with *Pearsonema plica*. Prompt identification and treatment with anthelmintic therapy resulted in an excellent prognosis. This case highlights the importance of considering parasitic etiologies in feline lower urinary tract disease (FLUTD), particularly in cases unresponsive to conventional therapies.

Introduction
Lower urinary tract disease is a common clinical presentation in feline patients, often associated with conditions such as cystitis, urolithiasis, or bacterial infection. However, parasitic infections, though uncommon, remain an important differential diagnosis.
Urinary capillariosis is caused by *Pearsonema plica* (formerly *Capillaria plica*), a nematode that inhabits the urinary bladder and associated structures. While more frequently reported in canines, feline infections are increasingly recognized in veterinary literature. This report documents a confirmed case and underscores diagnostic and therapeutic considerations

Patient Presentation and Clinical Signs
Paulie was presented for evaluation of lower urinary tract signs, including:
* Hematuria (blood in urine)
* Dysuria (painful urination)
* Pollakiuria (frequent, small-volume urination)
* Observable discomfort during urination
The owner also reported inappropriate urination outside the litter box. Physical examination findings were consistent with inflammation of the lower urinary tract, suggesting cystitis or urethritis.
Diagnostic Findings
A complete urinalysis was performed, including microscopic evaluation of urine sediment. Findings included:
* Presence of operculated, barrel-shaped eggs with bipolar plugs
* No significant bacterial growth observed
* Evidence of urinary tract inflammation
The parasitic ova were morphologically consistent with *Pearsonema plica*, confirming a diagnosis of urinary capillariosis.
Pathophysiology of Urinary Capillariosis

*Pearsonema plica* is a thread-like nematode that localizes within the urinary bladder, ureters, or renal pelvis.
Transmission
Infection typically occurs through ingestion of infected earthworms, which serve as intermediate hosts harboring larval stages of the parasite.
Lifecycle and Infection
After ingestion, larvae migrate to the urinary tract, where they mature into adult worms and embed within the mucosa. Eggs are subsequently shed in the urine.
Although infections may be subclinical, higher parasite burdens can cause:
* Mucosal irritation and inflammation
* Hematuria
* Dysuria and pollakiuria
* Behavioral changes such as periuria
Management and Treatment Protocol**
Diagnosis
* Confirmed via identification of characteristic eggs on urine sediment examination
Pharmacological Intervention
Treatment included administration of anthelmintic agents, such as:
* Fenbendazole
* Ivermectin
These medications are effective in eliminating adult worms and resolving clinical signs.
Supportive Care
* Monitoring urinary function
* Ensuring adequate hydration
* Environmental management to reduce reinfection risk
Prognosis
The prognosis for feline urinary capillariosis is excellent when appropriate treatment is administered. Most patients respond rapidly to anthelmintic therapy, with resolution of clinical signs and elimination of the parasite.
Discussion
This case emphasizes the importance of including parasitic infections in the differential diagnosis of feline lower urinary tract disease, particularly when patients fail to respond to standard treatments such as antibiotics.
Although rare, urinary capillariosis may be underdiagnosed due to:
* Intermittent shedding of eggs
* Lack of routine sediment examination
* Misattribution to idiopathic cystitis
Veterinarians should maintain clinical suspicion, especially in outdoor cats or those with potential exposure to intermediate hosts.
Conclusion
This report documents a confirmed case of feline urinary capillariosis in a domestic shorthair cat presenting with classic lower urinary tract signs. Diagnosis was achieved through urinalysis, and treatment with anthelmintics resulted in a favorable outcome.

Recognition of this condition is critical for accurate diagnosis and effective management of atypical or persistent urinary tract cases in feline patients.
Key Takeaway
💡 In cases of persistent or recurrent feline cystitis that do not respond to conventional antibiotic therapy, urinary parasites such as *Pearsonema plica* should be considered as a primary differential diagnosis.
*References
* Bédard, C., et al. (2002). Urinary capillariosis in a cat: A case report.
* Rossi, M., et al. (2011). Clinical manifestations of *Capillaria plica* infection in cats.
* Whitehead, M. (2009). Urinary capillariosis in a domestic feline.
* Studzińska, M. B., et al. (2015). Diagnosis and treatment of urinary capillariosis.
* Knaus, M., et al. (2014). Efficacy of anthelmintic treatments in parasitic infections.
* Traversa, D., & Di Cesare, A. (2016). Feline parasitic infections: Diagnosis and management.
***By Saeed Bashir DVM***