Todayโs path rounds are on ๐ฌ๐๐๐๐ฅ๐ ๐ญ๐ก๐ซ๐จ๐ฆ๐๐ข, more scientifically known as ๐๐๐ฅ๐ข๐ง๐ ๐๐จ๐ซ๐ญ๐ข๐ ๐ญ๐ก๐ซ๐จ๐ฆ๐๐จ๐๐ฆ๐๐จ๐ฅ๐ข๐ฌ๐ฆ!
๐๐ก๐๐ญ ๐ข๐ฌ ๐ข๐ญ?
Aortic thromboembolism is when there is a blood clot that obstructs part of the aorta. In particular, this type of thrombus tends to lodge where the aorta splits into two arteries to run down each hind leg, an area referred to as the ๐ฌ๐๐๐๐ฅ๐.
๐๐ก๐จ ๐ ๐๐ญ๐ฌ ๐ข๐ญ?
This condition is almost exclusively seen in cats!
๐๐ก๐๐ญ ๐๐๐ฎ๐ฌ๐๐ฌ ๐ข๐ญ?
The major predisposing factor to this condition is heart disease, specifically ๐ก๐ฒ๐ฉ๐๐ซ๐ญ๐ซ๐จ๐ฉ๐ก๐ข๐ ๐๐๐ซ๐๐ข๐จ๐ฆ๐ฒ๐จ๐ฉ๐๐ญ๐ก๐ฒ. In this condition, the muscles of the heart become thickened with a small ๐ฅ๐ฎ๐ฆ๐๐ง, or space within the heart. This causes blood flow through the heart to become turbulent, which may predispose the cat to developing blood clots. These clots then move from the heart down the aorta, to cause a saddle thrombus.
๐๐ก๐ฒ ๐ข๐ฌ ๐ญ๐ก๐ข๐ฌ ๐ ๐ฉ๐ซ๐จ๐๐ฅ๐๐ฆ?
Blocking the blood flow to an entire hind limb, or even both hind. limbs, has serious consequences. Not only is this immensely painful, but the reduced blood flow causes tissue ๐ง๐๐๐ซ๐จ๐ฌ๐ข๐ฌ (death of cells) which can lead to the skin sloughing and loss of muscle. If the clot is suddenly broken down or removed, the cat can suffer from a ๐ซ๐๐ฉ๐๐ซ๐๐ฎ๐ฌ๐ข๐จ๐ง ๐ข๐ง๐ฃ๐ฎ๐ซ๐ฒ, which causes a sudden influx of large numbers of inflammatory cells trying to clean up the dead tissue, and producing ๐จ๐ฑ๐ข๐๐๐ญ๐ข๐ฏ๐ ๐๐ ๐๐ง๐ญ๐ฌ (a toxic waste product from clean up) that further damages the tissue.
๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐๐ข๐๐ ๐ง๐จ๐ฌ๐๐?
Cats presenting with saddle thrombi have 5 major clinical signs on affected hind limbs, referred to as the 5 Ps: pain, ๐ฉ๐๐ซ๐๐ฌ๐ข๐ฌ (weakness), pulselessness, ๐ฉ๐จ๐ข๐ค๐ข๐ฅ๐จ๐ญ๐ก๐๐ซ๐ฆ๐ฒ (same temperature as the environment) and ๐ฉ๐๐ฅ๐ฅ๐จ๐ซ (pale tissues). Based on the clinical suspicion, the veterinarian will then take an X-ray or do an ultrasound to assess for the heart disease which underlies this condition.
๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐ญ๐ซ๐๐๐ญ๐๐?
Treatment is largely centered around pain control and anti-coagulant drugs to prevent further thrombi and break down the existing one. Unfortunately, even with treatment, the prognosis for these cases is extremely poor, with a low chance of full recovery, so these cats are often euthanized.
๐๐ก๐จ๐ญ๐จ๐ฌ
1-3) Examples of saddle thrombi seen at necropsy.
4) A cross-section of a heart with hypertrophic cardiomyopathy, which can lead to saddle thrombi. See how small the lumen of the heart is?
๐๐จ๐ฎ๐ซ๐๐๐ฌ
Maxie, G. Jubb, Kennedy and Palmerโs Pathology of Domestic Animals, Volume 3. Sixth Edition.
Brooks, W. Feline aortic thromboembolism (FATE or saddle thrombus). Veterinary Partner, 2012.
Photos 1, 2 and 3 courtesy of University of Calgary Diagnostic Services Unit.
Photo 4 courtesy of Noahโs Arkive.
