A dog coughing up blood after a seizure can be extremely alarming, particularly when the bleeding occurs soon after the episode.
Blood coming from the mouth or airways should not be assumed to be a normal part of recovering from a seizure, especially when your dog is having difficulty breathing or remains weak or confused afterward.
The timing of the coughing, the appearance and amount of blood, how your dog is breathing, and how quickly they recover after the seizure are important details for a veterinarian to assess.
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Dog Coughing Blood After Seizure: Why It Happens
A dog may cough blood after a seizure because of irritation or injury to the mouth or airway, aspiration of saliva or vomit, respiratory disease, or another condition affecting the lungs or blood vessels.
Coughing up blood, known as hemoptysis, is a respiratory sign that can have several possible causes.
A seizure itself does not necessarily cause a dog to cough blood. The blood may instead come from an irritated area of the mouth or throat, or from the respiratory tract. Determining where the blood originated is important.
Dog Coughing Blood After Seizure: Common Causes
Mouth or Throat Irritation
A dog may have increased saliva and unusual muscle activity during a seizure. The mouth or throat can become irritated, and blood from the gums, tongue, or another small injury may be noticed when the dog coughs or clears their throat.
Blood originating from the mouth may look different from blood coming from deeper in the respiratory tract.
If bleeding appears to continue, is more than a small amount, or you cannot determine where it is coming from, your dog should be examined.
Read more: Old Dog Coughing Then Seizure (Causes and treatment)
Aspiration of Saliva
Dogs can produce considerable saliva during a seizure. If saliva enters the airway, it can cause coughing and airway irritation afterward.
Aspiration can sometimes progress to aspiration pneumonia. Signs can include coughing, lethargy, loss of appetite, fever, rapid breathing, and breathing difficulty.
Blood in the cough is not something to automatically attribute to simple saliva aspiration, however. Persistent coughing or blood should be assessed by a veterinarian.
Aspiration of Vomit or Regurgitated Material
Some dogs vomit or regurgitate around the time of a seizure. If stomach contents enter the airway, they can irritate the respiratory tract and potentially cause aspiration pneumonia.
Affected dogs may develop coughing, fever, lethargy, reduced appetite, rapid breathing, or breathing difficulty.
If your dog vomited before or after the seizure and subsequently began coughing blood, tell your veterinarian because this history can be important when determining the cause.
Respiratory Tract Injury or Inflammation
Bleeding can originate somewhere within the respiratory tract. Inflammation, irritation, infection, foreign material, or other airway problems can cause coughing, sometimes with blood or blood-tinged mucus.
Respiratory disease can also cause rapid breathing, labored breathing, exercise intolerance, nasal discharge, and other changes.
The seizure may therefore be coincidental rather than the direct cause of the bleeding.
Read more: Dog Coughing Then Seizure (What it means)
Pneumonia
Pneumonia can cause coughing, lethargy, loss of appetite, fever, and respiratory distress. Aspiration is one possible cause, particularly when material such as vomit enters the lungs.
A dog may not develop every sign immediately. If coughing continues after a seizure or becomes worse over the following hours, veterinary assessment is important.
Blood Clot or Blood Vessel Problems
Certain cardiovascular or blood-vessel conditions can cause a dog to cough up blood or bloody mucus. Blood clots affecting the lungs can cause sudden breathing difficulty and may be accompanied by coughing blood.
These conditions can be serious and require prompt veterinary investigation, particularly when breathing changes occur.
Underlying Respiratory Disease
An existing respiratory condition may become noticeable around the same time as a seizure. Infections, inflammatory airway disease, parasites, and other lung conditions can cause persistent coughing.
For example, some lung parasites can produce a chronic or intermittent cough and, in more advanced cases, weakness or breathing difficulties.
If your dog had been coughing before the seizure, the two symptoms may have a common underlying cause rather than the seizure directly producing the cough.
Seizure-Related Trauma
A seizure can cause involuntary movements that may result in minor trauma. A dog could injure the mouth or another area during the episode, and blood may subsequently be noticed.
However, significant or repeated bleeding should not be assumed to be from seizure-related trauma.
Your veterinarian may need to examine the mouth, airway, lungs, and overall health to identify the source.
Read more: Dog Coughing After Seizure (Here’s why)
When to Call or Visit the Vet
Coughing blood after a seizure warrants immediate veterinary assessment, particularly if the source of the blood is unclear or the coughing continues. Seek urgent veterinary care if you notice:
More than a small amount of blood or repeated bloody coughing
Rapid, labored, or difficult breathing
Pale, gray, or bluish gums
Severe weakness, collapse, or inability to recover normally
Repeated seizures or prolonged abnormal behavior
Persistent coughing, vomiting, or regurgitation
Marked lethargy, fever, or loss of appetite
Rapidly worsening symptoms
Respiratory distress and blood in coughed-up material can be associated with significant respiratory or circulatory disease and should not be monitored at home without veterinary guidance.
Dog Coughing Blood After Seizure: Treatment
Veterinary treatment for a dog coughing blood after a seizure starts with an examination of the mouth, airway, lungs, heart, and overall health, along with a detailed history of the seizure and what happened immediately before and afterward.
The veterinarian may recommend chest X-rays and blood tests to investigate aspiration, pneumonia, bleeding, infection, cardiovascular problems, or other underlying conditions.
Treatment depends on the cause and may include oxygen support, fluids, medication, treatment for infection, management of an underlying respiratory or cardiovascular condition, or seizure management.
Key Takeaway
Dog coughing blood after a seizure can have several possible explanations, including mouth or throat irritation, aspiration of saliva or vomit, respiratory disease, pneumonia, trauma, or problems involving the lungs and blood vessels.
A seizure does not automatically explain why a dog is coughing blood. Because blood in coughed-up material can indicate a respiratory or circulatory problem, the symptom deserves veterinary attention.
If your dog is coughing blood after a seizure, contact your veterinarian immediately. If there is significant bleeding, difficulty breathing, pale or bluish gums, collapse, severe weakness, repeated seizures, or rapidly worsening symptoms, seek emergency veterinary care immediately.