How to handle feline aortic thromboembolism - Veterinary Medicine
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How to handle feline aortic thromboembolism
A blocked artery caused by a thromboembolus occurs in almost one-third of cats with heart disease, resulting in devastating consequences that often start with pelvic limb paralysis. These clinicians help you detect the blockage, explore newer treatment options, recognize which treatments are not recommended, and identify prevention strategies.



Table 1: Previous Studies Outlining Initial Treatment of Cats with Aortic Thromboembolism, Percent Discharged from the Hospital, and Median Survival Time
The prognosis for cats with ATE remains guarded to poor. Most cats die or are euthanized as a result of the disease. Table 1 summarizes various treatment and survival times. Studies have shown survival to discharge rates of only 27% to 35% with various treatment strategies.1,2,37,38 Median survival times of cats surviving to discharge range from 117 to 345 days.1,2,4,37

Body temperature is one of the most important prognostic indicators; hypothermia at presentation has been consistently associated with poor prognosis. In one study, a model predicting survival showed the probability of survival was 50% with a rectal temperature of 98.9 F (37.2 C) and less than 25% at 96 F (35.6 C).2

The number of hindlimbs affected also impacts prognosis. Bilaterally affected cats have a worse prognosis than unilaterally affected cats.2 Cats with thromboemboli that affect the forelimbs have a better prognosis than those with thromboemboli that affect the hindlimbs.9

Concurrent CHF does not affect survival to discharge but reduces survival time.2 Cats are at high risk for future thromboembolic events as 25% to 47% experience future ATE episodes.1,2,37


ATE is a serious disease process in cats affecting close to 30% of cats with cardiac disease.4 Treatment involves pain control, prevention of continued thrombus formation, limiting the effects of reperfusion injury by maintaining tissue perfusion, and managing the underlying cause. Hypothermia at presentation is a negative prognostic indicator. Re-thrombosis is a major concern. Current recommendations for preventing future ATE episodes include aspirin therapy (at various doses), LMWH, and clopidogrel either alone or in combination. At this time, no preventive strategy has proved effective or superior to any other strategy. Long-term prognosis is guarded to poor as most cats will eventually die of complications of ATE or CHF.

Timothy Koors, DVM
H. Cecilia Marshall, DVM, DACVIM (cardiology)
Veterinary Specialty Services
1021 Howard George Drive
Manchester, MO 63021


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