Introduction
A dog coughing up blood can be very alarming for pet owners. Blood in a dog’s saliva, phlegm, or coming from the nose or mouth is called hemoptysis. Seeing blood when a dog coughs is a concerning symptom that requires veterinary attention. There are several potential reasons that could cause a dog to cough up blood, ranging from mild to severe underlying conditions. It’s important to understand the possible causes so you can get your dog appropriate treatment. This article will provide an overview of the reasons a dog may cough up blood and steps for diagnosis and care.
Heartworm Disease
Heartworm disease is caused by parasitic worms called Dirofilaria immitis that infest the heart and pulmonary arteries of affected dogs. Mosquitoes transmit heartworm larvae to dogs through bites. The larvae then migrate to the heart and pulmonary arteries where they mature into adult worms over several months.
As the number of worms increases, they cause inflammation and damage to the blood vessels and lungs. This can lead to coughing as an early symptom. Later on, affected dogs may cough up blood as the worms and associated inflammation damage the lungs and airways (Veterinary Emergency Group). The presence of the heartworms also puts strain on the heart, which can lead to congestive heart failure.
Heartworm disease is a progressive and potentially fatal condition but can be prevented through monthly use of heartworm prevention medication prescribed by a veterinarian. Dogs should also be tested annually for heartworm infection. If caught early, heartworm disease can be treated, but the treatment itself can also cause dogs to cough up blood as the worms die and break up in the dog’s system.
Trauma
Trauma to a dog’s chest or airways can cause bleeding and coughing up blood. Blunt force trauma from being hit by a car or other accident can cause pulmonary contusions, bruising and bleeding in the lungs (Veterinary Emergency Group, 2022). Symptoms include coughing up blood, vomiting blood, rapid breathing, and signs of chest injuries like broken ribs. These contusions can be life-threatening.
Ingestion of caustic substances or toxins can chemically burn and damage the esophagus, stomach, and lungs, leading to bleeding and coughing up blood. Common toxins include antifreeze, rodent poison, acids, and petroleum products. Treatment involves decontamination, oxygen support, and managing shock. Preventing access to toxins is key.
Foreign objects like bones, sticks, balls, or other items can become lodged in the throat, puncture the esophagus, or obstruct breathing. This can cause gagging, choking, retching, wheezing, and coughing up blood as the object scrapes delicate tissues. Immediate veterinary care is needed for removal. Slowing down during play and meals can help prevent foreign object aspiration and ingestion.
Bleeding Disorders
Some bleeding disorders can cause dogs to cough up blood. Common bleeding disorders include:
Von Willebrand Disease
Von Willebrand disease (vWD) is the most common inherited bleeding disorder in dogs. It affects the blood’s ability to clot properly. Dogs with vWD can experience nosebleeds, bleeding gums, blood in the stool, and prolonged bleeding from minor wounds or surgery. It is caused by a deficiency of von Willebrand factor, a protein involved in platelet adhesion and blood clotting (VCA Animal Hospitals).
Hemophilia
Hemophilia is a genetic disorder that impairs the body’s ability to form blood clots. It is caused by a deficiency in clotting factors VIII or IX. Dogs with hemophilia can experience spontaneous bleeding, including coughing up blood. They are also at risk of excessive bleeding from injuries, surgery, or routine procedures like vaccinations (Merck Veterinary Manual).
Thrombocytopenia
Thrombocytopenia is caused by abnormally low levels of platelets in the blood. Platelets are involved in clot formation. Dogs with thrombocytopenia can spontaneously bleed or bruise. They may cough up blood from the lungs or nose. Thrombocytopenia can be inherited or acquired from other medical conditions (Merck Veterinary Manual).
Lung Disease
Some of the most common lung diseases that can cause a dog to cough up blood include pneumonia, pulmonary edema, and lung cancer. Pneumonia is an inflammation of the lungs often caused by a bacterial, viral, or fungal infection. It can lead to bleeding in the airways as the lungs struggle to clear themselves of infection. Dogs with pneumonia may cough up frothy blood or blood-tinged sputum. Treatment involves antibiotics and medications to open up the airways.
Pulmonary edema occurs when fluid leaks into the lungs, making it difficult for the dog to breathe. The blood vessels in the lungs can also leak blood into the airways, resulting in coughing up blood. Some causes are heart failure, smoke inhalation, trauma, or a blood clot in the arteries of the lungs. Pulmonary edema is a medical emergency and requires prompt veterinary treatment such as diuretics, oxygen therapy, and medication for the underlying condition.
Lung tumors or cancer can damage the airways and blood vessels, leading to bleeding. Dogs may cough up large amounts of blood if the tumor erodes a major blood vessel. Lung cancer treatment depends on the type, location, and spread of the tumor. Options include surgery, chemotherapy, radiation therapy, and medications to help with breathing issues.
Heart Disease
Heart disease is a common cause of coughing up blood in dogs. When a dog has heart failure, blood can back up into the lungs causing pulmonary edema and hemoptysis (coughing up blood). Heart failure is a condition where the heart is unable to pump sufficient blood to meet the body’s needs. It can be caused by various acquired and congenital heart diseases in dogs such as valvular insufficiency, cardiomyopathy, and endocarditis (Dog Coughing and Heart Disease).
Valvular heart disease, where the valves of the heart deteriorate, is one of the most common causes of congestive heart failure in dogs. It causes turbulent blood flow and backflow of blood which strains the heart. Older small breed dogs are predisposed. Eventually blood backs up leading to cough, exercise intolerance, and coughing up blood (Coughing In Dogs With Heart Disease).
Abnormal heart rhythms or arrhythmias put dogs at risk of blood clots which can travel to the lungs causing hemoptysis. Certain breeds like Boxers and Dobermans are prone to arrhythmias. Getting an annual vet check including listening for murmurs and arrhythmias is important for early detection and treatment.
Gastrointestinal Disease
Gastrointestinal (GI) diseases are common causes of coughing up blood in dogs. Sources of bleeding in the GI tract include ulcers, cancerous growths, and foreign objects that can tear or perforate the esophagus, stomach or intestines.
Ulcers can form in the esophagus, stomach or upper intestines of dogs. These painful sores erode the tissue lining the GI tract. As blood vessels are exposed, ulcers can bleed and cause dogs to cough up blood. Ulcers may be caused by factors like stress, certain medications, bacterial infections, or foreign bodies.
Cancerous growths in the esophagus, stomach or intestines can also lead to bleeding and coughing up blood. Tumors may erode into underlying blood vessels. Common GI cancers in dogs include adenocarcinoma, leiomyosarcoma, and mast cell tumors.
Sharp foreign objects that a dog swallows, like bones or sticks, can puncture or tear the GI tract during passage. This leads to acute bleeding and coughing up blood. Less common causes of GI bleeding include blood clotting disorders or side effects of medications like NSAIDs or steroids.[1]
Kidney Disease
Kidney disease is one of the main causes of dogs coughing up blood (VCA Animal Hospitals). The kidneys have many important functions like filtering waste from the blood, controlling blood pressure, and producing red blood cells. Chronic kidney disease (CKD) and acute kidney injury can result in a buildup of toxins, fluid retention, and anemia which can lead to coughing up blood.
There are several specific kidney disorders that can cause a dog to cough up blood:
- Glomerulonephritis – Inflammation and damage to the kidney’s filtering units causing protein and blood in the urine. This results in anemia and buildup of waste products.
- Cancer – Kidney tumors or masses that damage kidney tissue and function. This cancer spread can also cause bloody coughs.
- Infections – Bacterial, viral, or fungal kidney infections that impair function and create inflammation. Pyelonephritis is a severe kidney infection that can lead to coughing up blood (Brightcarevet.com).
Kidney disease usually has a gradual onset, so early detection allows for better management. Symptoms include increased water consumption, weight loss, vomiting, diarrhea, and bad breath (Sharon Lakes). Tests like bloodwork, urinalysis, imaging, and biopsies help diagnose the specific cause of kidney malfunction.
Diagnosis
A veterinarian will begin diagnosing the cause of a dog coughing up blood by performing a thorough physical exam. They will check the dog’s vital signs, listen to the heart and lungs with a stethoscope, and examine the mouth, nose and throat for signs of injury or abnormalities.
Diagnostic imaging tests may also be recommended, such as X-rays or ultrasound of the chest to check for an infection or fluid in the lungs. Endoscopy involves using a small camera on a flexible tube to examine the airways and esophagus. This helps identify any foreign objects, masses, ulcers or other issues that could be causing bleeding.
According to Veterinary Emergency Group, endoscopy is considered the best diagnostic tool for exploring the cause of coughing up blood, as it allows vets to visualize the pharynx, larynx, trachea, bronchi, and esophagus.
Other diagnostic tests like bloodwork, urinalysis, heartworm test, coagulation tests, and parasite screening may also be performed. These help rule out underlying conditions that could contribute to hemorrhage.
Treatment
The treatment for a dog coughing up blood will depend on the underlying cause. The vet will first need to diagnose the root issue before determining the proper treatment plan. Some general treatment considerations include:
Addressing the underlying cause – If a specific condition like heartworm disease, bleeding disorder, or trauma is identified as the cause, treatment will focus on resolving that primary issue. For example, heartworm disease is treated with medications to kill heartworms, while trauma may require surgery.
Supportive care – Most dogs coughing up blood will need supportive care while the underlying problem is addressed. This can include intravenous fluids, blood transfusions, oxygen therapy, rest, medication for nausea or pain, and nutritional support. Preventing further bleeding and managing anemia are priorities.
Blood clotting medication – Medications that help the blood clot may be used short-term to control bleeding.
Antibiotics – If there is concern about secondary pneumonia or infection, antibiotics may be prescribed.
Emergency care – Dogs coughing up large amounts of blood or having breathing difficulties may need emergency veterinary treatment to stabilize them before determining the cause.
Follow up care – Once the initial issue is treated, ongoing vet visits are key to monitor the dog’s progress and watch for potential complications or recurrence of symptoms.
With appropriate treatment matched to the underlying problem, many dogs can recover well when coughing up blood. But quick veterinary care is essential.