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Pulmonary Thromboembolism (PTE) in Dogs and Cats

Posted May 20, 2014 in Dog Diseases & Conditions A-Z

Sad dog laying down

Pulmonary thromboembolism, often abbreviated “PTE” in veterinary medicine, is a life-threatening, acute blood clot that develops within the lungs. Pulmonary thromboembolism results in difficulty breathing and can occur in both dogs and cats. While rare, PTE can be fatal and result in sudden death.

What causes a pulmonary thromboembolism?
In human medicine, pulmonary thromboembolism is often the result of a deep vein thrombus (often abbreviated “DVT”) that develops somewhere in the blood vessels (veins) of the body. This is one of the reasons why medical doctors will tell you to walk around or use compression socks when you are on a long plane ride. If you develop a DVT, you are at a significantly higher risk of this clot “blowing off” and getting stuck in your lungs, causing a pulmonary embolism.

In veterinary medicine, DVT is less of a common occurrence. That said, we can still see the development of PTE secondary to certain problems within the body.

Animals that are more likely to clot (called a “hypercoagulable”) are predisposed to developing PTE. Typically, this occurs under the following conditions:

  • Animals with heart disease
  • Abnormal blood flow (called “blood stasis”) in the heart vessels
  • Animals on chronic steroids (e.g., prednisone, prednisolone, dexamethasone, etc.)
  • Underlying red blood cell injury (secondary to diseases like immune-mediated hemolytic anemia, etc.)
  • Metabolic problems where there is an abnormally low protein in the body (due to loss through the kidneys, liver, or gastrointestinal tract)
  • Cancer
  • Pancreatitis (i.e., inflammation of the pancreas)
  • Severe inflammation in the body
  • Severe trauma
  • Surgery
  • Numerous other causes

Symptoms of a pulmonary thromboembolism include:

  • Acute, sudden difficulty breathing
  • Constant panting
  • Anxiety, restlessness, pacing
  • An increased respiratory rate > 40 breaths per minute (bpm)
  • Open mouth breathing
  • Blue-tinged gums (which indicates severe difficulty and possibly death if not treated immediately)
  • Stretching the neck out to breathe
  • Sitting up to breathe, with the front legs/elbows spread out (like a English bulldog)
  • Using the abdomen to breathe better (you’ll notice the sides of the belly heaving in and out more)
  • Sudden death

If you notice any of these signs, an immediate trip to the veterinarian or emergency veterinarian is imperative, or death may be imminent.

Diagnosing a pulmonary thromboembolism
Once your pet is at the veterinarian, she’ll probably stabilize your dog or cat with oxygen therapy immediately. Then, diagnostic tests can be run to find out what is going on (as there are numerous causes

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Justine has more than 18 years of experience in the veterinary industry and is a board-certified emergency critical care veterinary specialist and toxicologist as well as the CEO and founder of Vetgirl. She is also a founding member of IDEXX’s Pet Health Network team.