Why is my dog coughing?

Infectious tracheobronchitis — commonly known as kennel cough — is caused by Bordetella bronchiseptica and often in combination with canine parainfluenza virus or other respiratory pathogens. It produces a distinctive harsh, dry cough that can sound like your dog is trying to clear something from the throat. Dogs that attend daycare, boarding facilities, dog parks, or training classes are at higher risk due to exposure in group settings.

Canine influenza is another infectious cause of coughing that can produce fever, lethargy, and nasal discharge in addition to cough. Most healthy dogs recover from influenza, but it can be more serious in very young, elderly, or immunocompromised dogs.

Other infectious agents — including canine respiratory coronavirus and Mycoplasma — can also cause respiratory signs. In many cases, these infections are self-limiting in healthy dogs, but veterinary evaluation is recommended to rule out more serious causes and to determine whether treatment is needed.

Tracheal collapse is a progressive condition most common in small and toy breeds such as Yorkshire Terriers, Pomeranians, Chihuahuas, and Poodles. The cartilage rings that keep the trachea open weaken over time, causing the airway to flatten during breathing. This produces a characteristic goose-honk cough that worsens with excitement, exercise, or pressure on the neck from a collar.

Reverse sneezing is a different phenomenon that can be mistaken for coughing or choking. It involves rapid, forceful inhalations through the nose and is usually brief and self-resolving. While reverse sneezing is generally harmless, frequent episodes may warrant a veterinary evaluation to rule out underlying nasal or pharyngeal irritation.

Tracheal irritation from inhaled irritants, chronic dry air, or environmental allergens can also produce coughing. Your veterinarian can help determine whether the cough is originating from the trachea and what steps are appropriate.

Chronic bronchitis is diagnosed when a dog has a persistent cough for more than two months without an identifiable underlying cause. The cough is typically dry or produces a small amount of mucus, and it tends to worsen with exercise or excitement. Chronic bronchitis is more common in middle-aged and older small-breed dogs.

Allergic airway disease, sometimes called canine asthma or allergic bronchitis, can also cause coughing in response to inhaled allergens such as dust, pollen, or mold. The cough may be intermittent and seasonal in some dogs.

Diagnosis of bronchial disease often involves chest X-rays and sometimes a tracheal wash or bronchoalveolar lavage to collect samples from the airways for analysis. Treatment focuses on reducing airway inflammation and managing environmental triggers.

Bacterial pneumonia can develop as a primary infection or secondary to another condition such as a foreign body aspiration, immune suppression, or kennel cough. Signs include cough (often productive), fever, lethargy, loss of appetite, and difficulty breathing. Pneumonia can range from mild to life-threatening depending on the extent of lung involvement and the dog's overall health.

Viral pneumonia, including that caused by canine distemper or canine influenza, can produce similar signs. Aspiration pneumonia — caused by inhaling vomit, food, or liquid into the lungs — is another important cause, particularly in dogs with swallowing difficulties, megaesophagus, or after recent anesthesia.

Chest X-rays are the primary tool for diagnosing pneumonia, as they can reveal areas of consolidation or fluid within the lung tissue. Treatment typically involves antibiotics (when bacterial infection is present or suspected), supportive care, and monitoring. Dogs with pneumonia should be evaluated promptly by a veterinarian.

Congestive heart failure is one of the most common cardiac causes of coughing in dogs. When the heart cannot pump blood efficiently, fluid can back up into the lungs (pulmonary edema) or accumulate in the chest cavity around the lungs (pleural effusion). This fluid accumulation triggers coughing, which often worsens at night or when the dog is lying down.

Other signs of heart disease that may accompany coughing include exercise intolerance, increased respiratory rate, reduced appetite, and abdominal distension. Small-breed dogs are predisposed to degenerative mitral valve disease, while larger breeds may develop dilated cardiomyopathy.

Diagnosis of cardiac disease typically involves chest X-rays, an echocardiogram (ultrasound of the heart), and sometimes an electrocardiogram. Early identification and management of heart disease can help maintain quality of life and slow progression.

Difficulty breathing — characterized by rapid breathing, labored breathing, open-mouth breathing, or visible effort to move air — is an emergency sign that should not wait. Blue-tinged or pale gums indicate inadequate oxygenation and require immediate attention.

Coughing up blood (hemoptysis) can indicate serious conditions including severe infection, pulmonary hemorrhage, or advanced heart disease and should be evaluated promptly. Collapse, extreme lethargy, and high fever accompanying a cough also warrant urgent care.

Small-breed dogs with signs of tracheal collapse and brachycephalic breeds (Bulldogs, Pugs, Boston Terriers) with any respiratory distress should be evaluated quickly, as these dogs can deteriorate rapidly. If your dog is showing any of these signs, contact a veterinarian or emergency facility without delay.