Blood Clot in the Lungs in Dogs

Pulmonary thromboembolism (PTE) occurs when a blood clot develops and obstructs the one or more blood vessels which carry blood to the lungs. There are various underlying health problems that can lead to this condition, so it’s of utmost importance that your veterinarian determines what caused PTE. Blood clots, also known as pulmonary thromboemboli, can form in the dog’s veins anywhere in the body. The blood clot (or just one part of it) is then carried through the bloodstream, eventually getting stuck in one of the pulmonary blood vessels. As a result, blood can no longer flow through that particular blood vessel and reach the lung. The treatment outcome largely depends on the size of the blood clot, underlying cause and the onset of the symptoms. Unfortunately, the prognosis is poor in most cases. PTE affects all dog breeds, ages and genders.

Pulmonary thromboembolism (PTE) is a life-threatening acute blood clot that forms in the lungs and causes problems with breathing and pain. The condition is not very common in canines, but it is imperative to consult your veterinarian as soon as you notice the symptoms, as PTE can lead to the development of other medical issues and death. 

• Breathing problems
• Continuous panting
• Constantly breathing with open mouth
• Coughing up blood or bloody mucus 
• Anxiety
• Increased respiratory rate
• Reduced appetite 

• Heartworm disease 
• Endocarditis (inflammation of the endocardium)
• Cardiomyopathy (disease of the heart muscle) 
• Cancer 
• Cushing's disease
• Necrotizing pancreatitis 
• Protein-losing nephropathy (kidney disease) 
• Immune-mediated hemolytic anemia 
• Sepsis 
• Atherosclerosis (hardening and narrowing of the arteries)
• Diabetes mellitus 
• Trauma 
• Recent surgery

Pulmonary thromboembolism is not easy to diagnose, as the condition can be difficult to differentiate from pneumonia, pulmonary edema or hemorrhage, neoplasia and pleural effusion. In order to confirm that your dog is indeed suffering from PTE, your veterinarian will first thoroughly examine your dog and perform several laboratory tests, including complete blood count, electrolyte panel, and urinalysis. 

Since it’s vital to determine the underlying cause, you will have to provide your veterinarian with a complete medical history of your dog and be as precise as possible when it comes to describing the symptoms, as well as any unusual behavior that preceded the onset of the condition. Your veterinarian will then perform routine diagnostic tests such as arterial blood gas analysis and thoracic radiography, though chances are that these tests won’t be able to confirm PTE. A coagulation profile and heartworm serology will also be done.

In addition, your veterinarian will perform X-rays and an echocardiogram, which can often enable them to detect any abnormalities and make a diagnosis. Some veterinary clinics will also use spiral CT angiography or selective pulmonary angiography to diagnose PTE, as these imaging techniques are used with great precision to diagnose PTE in humans.

To stabilize your dog, your veterinarian will begin therapy before treating the underlying condition. Your pet will receive oxygen therapy and supportive care with the purpose of preventing the development and recurrence of blood clots. 

Some veterinarians may choose to give your dog anticoagulants such as warfarin, coumadin or heparin, but these blood thinners cannot dissolve the existing blood clot. They can, however, prevent the development of new blood clots. Your dog can also take aspirin or clopidogrel along with the blood thinners, but you should keep in mind that these antiplatelet medications are not a replacement for anticoagulants. Thrombolytic therapy is another way of treating pulmonary thromboembolism, but blood clotting medications such as streptokinase and tissue plasminogen activator are expensive and can cause serious complications in dogs, so most veterinarians do not recommend the use of these drugs.

You will have to take your dog for regular check-ups to make sure that they are recovering well and not experiencing any complications from the use of anticoagulants. Your dog will probably take these meds for a couple of months, so it’s crucial to follow your veterinarian’s instructions and look out for the signs of PTE. Your veterinarian will recommend that you take your dog for frequent walks, as moderate physical activity can enhance blood flow and prevent future problems. They will also advise you on certain lifestyle changes in accordance with your pet’s medical condition. 

Sadly, the prognosis for pulmonary thromboembolism in dogs is usually not positive, with many canines succumbing to the condition. Moreover, unless the underlying cause is correctly diagnosed and treated, PTE will recur in most pets. Because of this, veterinarians urge dog owners to seek help as soon as they notice breathing problems, seeing as the best thing you can do for your pet is to react promptly and properly.