Coughing Up Blood in Dogs

It is alarming to watch your dog cough up blood, and there are several reasons he may be doing so.  The underlying causes of coughing up blood can be severe and life-threatening.  It is important to determine the cause and seek treatment as soon as possible.  Some of the causes of coughing up blood include:

• Tuberculosis (a very rare disease in dogs)
• Pulmonary vascular disease
• Hematemesis (vomiting of blood from the digestive tract)
• Blood clotting disorders

Blood that is coughed up is usually associated with the lungs and respiratory system, but you may also see your dog vomit up blood with a cough.

Passing blood, either through a respiratory cough or by vomiting can point to a serious medical condition.

Tuberculosis

Tuberculosis is a bacterial infection affecting the respiratory systems.  It is spread through inhalation and can pass from people to dogs.  In advanced stages, your dog will show signs of jaundice and will cough up blood.  The disease mostly affects young dogs who have not yet built up healthy immune systems as well as dogs with suppressed immune systems.  

Pulmonary Vascular Disease

Pulmonary vascular disease encompasses several potential conditions where blood can be passed into airways and coughed up.  Heart disease associated with blood clots may cause your dog to cough up blood whereas a heartworm infection can push blood into the airways.  Pulmonary hypertension, or high blood pressure, can develop when the arteries are narrowed or blocked, leading to coughing and spitting up blood from the lungs.  

Hematemesis

Unlike blood that is spat up from the lungs, blood that originates in the digestive tract and is vomited up is associated with hematemesis.  Afflictions of the stomach and esophagus may cause blood to be vomited up, such as stomach ulcers or possibly gastric cancer.  Gastric cancer more commonly affects dogs 8 to 10 years of age or older.

Blood Clotting Disorders

When a dog cannot clot their blood properly, they are more prone to internal bleeding, which can occur at any point in the body. When bleeding occurs in the respiratory or gastrointestinal tract, a dog may cough up blood. Rat bait toxicity, for example, can cause coagulation issues.

If you notice your dog is coughing up blood, either from his lungs or in vomit, you should seek immediate medical assistance to rule out an infection, such as tuberculosis.  Tuberculosis, in its advanced stage, can be fatal and will result in death.  Unfortunately, tuberculosis is not usually treated, and dogs are euthanized for public safety.

Your veterinarian will ask you a serious of health questions concerning your dog, including any contact with humans or other animals that might have tuberculosis.  Tuberculosis is usually confirmed post-mortem, so diagnosis is made based on exposure to the bacteria.  

If tuberculosis, which is very rarely seen in dogs, is ruled out your veterinarian will run blood work to determine if your dog is suffering from heartworm disease.  An X-ray of the chest may also show an enlarged heart and can predict the possibility of complications related to the treatment of heartworms.  

An injectable drug is administered after confirming your dog is suffering from heartworm disease, and you veterinarian will develop an injection schedule according to your dog’s condition.  Antibiotics are also usually given to treat secondary infections caused by bacteria inside the heartworms.  The medication will kill the heartworms within a few days of treatment and as they break up the worm fragments will be carried by the bloodstream to the lungs where they are eventually reabsorbed into the body.  It is essential to keep your as calm as possible for the first month, post-treatment, and not be allowed to exercise.  You must follow your veterinarian’s strict instructions and return for a follow-up injection to kill the “baby heartworms,” known as microfilariae, to prevent a new heartworm cycle.  

Your dog may be vomiting up blood for a number of reasons.  Your veterinarian will ask you when you first noticed the symptoms as well as the color and quantity of the blood.  You will also need to give your vet a full medical history including any medications your dog has taken or chemical exposures.  Other symptoms, such as an accompanying fever, diarrhea, or shock will also help the veterinarian diagnosis the reason your dog is vomiting up blood.  Treatment for hematemesis will depend on the cause of the bloody vomit.  

A significant loss of blood will require a blood or plasma transfusions and well as fluid therapy to balance shock or dehydration symptoms.  Chronic occurrences where small amounts of blood are vomited up may indicate ulcers or gastritis, and your veterinarian will treat your dog with antacids to help manage the condition while developing a plan to treat the underlying condition.

Sometimes, blood that comes from the mouth can be confused for blood that is coughed up. Your vet will assess for e.g. a dental abscess, gum ulcer or tongue laceration that may be bleeding.

The underlying causes of coughing up blood are vastly different, and prevention of each of these possible conditions should be a regular part of your dog’s healthy lifestyle.  Preventing bacterial infections, such as tuberculosis, requires reducing your dog’s potential exposure to the disease.  You must keep your dog away from any member of your family or another person who is known or suspected to have tuberculosis.  Additionally, do not allow your dog to feed on the carcass of dead animals, both wild or livestock, as animal remains may be infected with the bacteria.  

Some pulmonary vascular diseases, like hypertension, cannot be easily prevented, but a healthy diet and exercise can help keep your dog trim and possibly prevent plaque from building up in his arteries (a rare occurrence in dogs).  Conversely, heartworm disease is a preventable condition through the use of medication.  

Unfortunately, you may not be able to prevent some of the diseases associated with hematemesis, such as gastric cancers.  However, with a healthy diet designed specifically for your dog based on his food intolerances and sensitivities, you can help prevent ulcers and gastritis. Keep your dog away from potential toxins such as cleaning products, rat baits and human medicines.