Pneumonia in Dogs: Causes, Symptoms and Treatment

Pneumonia in dogs is a serious respiratory infection that leads to lung inflammation. Pneumonia manifests through various symptoms and requires prompt treatment by a veterinarian who knows how to treat pneumonia in dogs.

Pet owners asking, “Can dogs get pneumonia?” must know that dogs develop pneumonia when bacteria, viruses, fungi, or parasites invade the lungs, compromising their ability to function.

Symptoms and signs of pneumonia in dogs include coughing, difficulty breathing, lethargy, fever, nasal discharge, and loss of appetite. Pneumonia progresses rapidly, leading to severe respiratory distress and potentially life-threatening complications if left untreated.

Diagnosing the stages of pneumonia in dogs and early intervention is crucial to improve the prognosis and prevent further complications. Diagnostic tests for pneumonia in dogs, such as blood work, tracheal wash, and bronchoscopy, identify the pathogens and select the most effective treatment.

Treatment for pneumonia involves antibiotics, oxygen therapy, and diagnostic tools such as X-rays to assess the severity of the condition.

What is Pneumonia in Dogs?

Pneumonia in dogs is a respiratory infection affecting the alveoli in their lungs, causing inflammation and breathing difficulties. “Pneumonia is an inflammation of the lungs and airways that causes breathing difficulties and deficiency of oxygen in the blood,” according to the article by Kuehn, N titled “Pneumonia in Dogs,” 2018. Various pathogens cause it and require prompt medical attention to prevent complications.

The main causes of pneumonia in dogs include inhaling infectious agents, aspiration, weakened immune systems, and chronic respiratory conditions. Respiratory problems in dogs range from mild to severe and often present with symptoms similar to pneumonia. Common respiratory issues include kennel cough, bronchitis, allergies, asthma, and collapsed trachea.

How do Dogs Get Pneumonia?

Dogs get pneumonia when pathogens such as bacteria, viruses, or fungi enter their respiratory tract, compromising their immune system's ability to fight off infections.

Inhaled irritants or foreign objects lead to aspiration pneumonia, where the lungs become inflamed from inhaled substances. “Dogs can get pneumonia from viral infection, aspiration injury, foreign body inhalation, and defects in clearance of respiratory secretions,” according to the study by Dear, J. titled “Bacterial Pneumonia in Dogs and Cats: An Update,” 2020.

Common bacterial sources of pneumonia in dogs include Bordetella bronchiseptica, Streptococcus zooepidemicus, and Mycoplasma. Viral infections like the canine distemper virus and canine influenza virus predispose dogs to pneumonia. Fungal pathogens such as Aspergillus and Cryptococcus cause serious respiratory issues.

Pneumonia is not directly linked to genetics, but genetics indirectly affect a dog's susceptibility to pneumonia. Certain breeds, immune deficiencies, and congenital conditions increase the risk of pneumonia.

What are the Common Causes of Canine Pneumonia?

The common causes of canine pneumonia are listed below.

Bordetella bronchiseptica: A primary cause of "kennel cough," which progresses to pneumonia if the infection spreads to the lower respiratory tract.
Streptococcus zooepidemicus: Known for causing severe respiratory infections and leading to pneumonia.
Escherichia coli, Pasteurella multocida, and Klebsiella pneumoniae: Other bacteria that cause pneumonia in immunocompromised dogs.
Canine Influenza Virus: Highly contagious and causes severe respiratory illness, periodically progressing to pneumonia.
Canine Distemper Virus: A virus that leads to severe pneumonia and other systemic signs.
Canine Parainfluenza Virus: Predisposes dogs to secondary bacterial pneumonia and is often involved in kennel cough complex.
Aspergillus: A common environmental fungus that causes pneumonia.
Blastomyces dermatitidis: Causes blastomycosis, which affects the lungs.
Histoplasma capsulatum: A disease that leads to histoplasmosis involving the lungs.
Lungworms: Parasites (e.g., Oslerus osleri, Capillaria aerophila) that infect the lungs and cause pneumonia.
Aspiration Pneumonia: A condition that occurs when a dog inhales foreign materials such as food, vomit, or liquids into the lungs, leading to inflammation and infection.
Chronic Respiratory Diseases: Conditions such as chronic bronchitis or collapsing trachea predispose dogs to pneumonia.
Immune System Compromise: Dogs with weakened immune systems due to illness or immunosuppressive medications are at higher risk of pneumonia.
Congenital Defects: Structural abnormalities in the respiratory system make dogs more susceptible.

How is Canine Pneumonia Compared to Kennel Cough?

Canine pneumonia differs from kennel cough in severity and causative agents. Kennel cough is commonly caused by Bordetella and occasionally by Streptococcus, while pneumonia results from various pathogens, leading to more severe lung inflammation and systemic symptoms. “Bordetella bronchiseptica, a gram-negative bacterium, is the main causative agent of kennel cough in dogs,” according to the study by Monteiro, L. titled “Diagnostic and Treatment Methods Used for Kennel Cough in Dogs,” 2019.

Canine pneumonia and kennel cough affect dogs' respiratory systems and are caused by bacterial and viral pathogens. Bordetella bronchiseptica is a common causative agent. The diseases spread through direct contact with infected dogs or contaminated environments, such as kennels or shelters. Vaccinations help prevent both conditions.

Kennel cough is milder, affecting the upper respiratory tract, while pneumonia is more severe, affecting the lower respiratory tract and requiring intensive treatment. Pneumonia leads to severe life-threatening complications like lung abscesses, unlike kennel cough.

What are Dog Pneumonia Symptoms?

The symptoms of pneumonia in dogs are listed below.

Coughing: Coughing is persistent and either dry or productive (producing mucus).
Difficulty Breathing: Dogs exhibit labored breathing, wheezing, or rapid shallow breaths.
Nasal Discharge: Mucus or pus-like discharge from the nose is common, sometimes accompanied by a foul odor.
Fever: Elevated body temperature, often manifesting as warmth to the touch, is noticeable in the ears and paws.
Lethargy: Dogs seem unusually tired or have a lack of energy.
Loss of Appetite: A decrease in interest in food or water is one of the signs of pneumonia in dogs.
Bluish Gums: Bluish gums indicate a lack of oxygen in the blood, a serious sign of respiratory distress.
Dehydration: Dogs become dehydrated due to fever and reduced fluid intake.
Weight Loss: Dogs lose weight over time due to decreased appetite and illness.
Vomiting: Some dogs vomit, especially if they are coughing a lot.

How is Pneumonia in Dogs Diagnosed?

Pneumonia in dogs is diagnosed through a physical examination, X-rays to assess lung inflammation, and nebulization to detect respiratory issues. Additional tests, such as blood work and cultures, identify the specific pathogens causing the infection. “Diagnosis of pneumonia in dogs is confirmed by clinical and laboratory findings, diagnostic imaging, and cytologic and microbiologic analysis of bronchoalveolar lavage or transtracheal wash fluid,” according to the study by Viitanen, S., Lappalainen, A., & Rajamäki, M. titled “Co‐infections with Respiratory Viruses in Dogs with Bacterial Pneumonia,” 2015.

X-rays provide a detailed look at the lungs, helping veterinarians pinpoint inflammation and fluid accumulation areas. Veterinarians evaluate the results to determine the extent of lung damage and the effectiveness of treatment.

Nebulization involves administering aerosolized medications to the dog, which reveal obstructive airway diseases or bronchial issues contributing to respiratory distress.

Blood work is essential for understanding the dog's overall health status, identifying any underlying causes of the infection, and selecting appropriate treatment options.

Can Pneumonia in Dogs Be Prevented with Vaccines?

Yes, pneumonia in dogs can be prevented through vaccines for specific viral infections, such as canine adenovirus, which leads to respiratory complications. Vaccination protocols recommended by veterinarians reduce the risk of viral pneumonia and protect dogs from severe respiratory illnesses.

Vaccines prepare a dog's immune system to combat harmful viruses that cause pneumonia by stimulating the production of antibodies against specific viral infections.

Following the vaccination schedules set by veterinarians ensures that dogs receive timely and adequate protection. Consistent vaccination safeguards dogs against pneumonia and strengthens their overall immunity, making them less susceptible to respiratory illnesses.

Is Pneumonia Caused by Inhalant Allergies in Dogs?

No, inhalant allergies in dogs do not directly cause pneumonia. Dog inhalant allergies cause respiratory symptoms such as coughing and sneezing but do not directly cause pneumonia.

Severe or chronic allergies compromise a dog's respiratory system, making them more susceptible to secondary infections that lead to pneumonia. “Allergen inhalation increases bone marrow-derived granulocyte progenitors in airway hyperresponsive dogs, but does not cause dog pneumonia,” according to the study by Inman, M., Denburg, J., Ellis, R., Dahlback, M., & O'Byrne, P. titled “Allergen-induced increase in bone marrow progenitors in airway hyperresponsive dogs: regulation by a serum hemopoietic factor,” 1996.

One of the risk factors of untreated dog inhalant allergies is developing fungal infections in the lungs triggered by exposure to mold spores or other allergens. The fungal infections progress to pneumonia if not addressed promptly, posing a threat to the canine’s overall health and well-being.

What are the Stages of Pneumonia in Dogs?

The stages of pneumonia in dogs are early, acute, severe, recovery, and chronic.

The early stage (initial infection) is characterized by mild coughing, slight nasal discharge, mild lethargy, and possibly a low-grade fever.

The acute stage (progression of infection) shows persistent and more severe symptoms such as increased coughing, nasal discharge, fever, lethargy, loss of appetite, and dehydration.

Pneumonia that progresses to the severe stage (consolidation) leads to severe coughing, labored breathing, cyanosis, high fever, extreme lethargy, and marked loss of appetite, often requiring urgent medical intervention.

Gradual improvement in breathing and reduced cough occurs in the recovery stage (resolution), with a return of appetite, decreased nasal discharge, and normalization of energy levels observed.

Pneumonia that is unresolved or lingers due to predisposing factors becomes chronic, leading to long-term changes in lung tissue and recurrent infections.

How Does Pneumonia Affect Dogs?

Pneumonia affects dogs by compromising their respiratory function, leading to reduced oxygen intake and systemic inflammation. The immune system responds to the infection, triggering lung inflammatory responses that impact overall health.

Oxygen therapy is necessary to support dogs with severe pneumonia and ensure proper oxygenation. “Aspiration pneumopathy in dogs can cause respiratory signs such as increased respiratory rate, effort, arterial hypoxaemia, or a requirement for oxygen therapy, but these signs usually resolve within 12 to 36 hours,” according to the study by Cook, S., Greensmith, T., & Humm, K. titled “Successful management of aspiration pneumopathy without antimicrobial agents: 14 dogs (2014-2021),” 2021.

Pneumonia in dogs results in accumulated fluid or pus in the lungs' air sacs, which impairs the exchange of oxygen and carbon dioxide. The disruption in gas exchange leads to lowered oxygen levels in the blood, causing further complications such as fatigue, weakness, and cyanosis. The inflammatory response triggered by pneumonia weakens the immune system, making the dog more susceptible to secondary infections and prolonged recovery.

What are the Risks of Long-Terms Pneumonia if not Treated?

The risks of long-term untreated pneumonia are listed below.

Chronic Respiratory Issues: The dog's quality of life is significantly impacted due to ongoing respiratory distress and discomfort.
Respiratory Failure: Respiratory failure is a critical condition that becomes fatal without immediate medical intervention.
Spread of Infection: The infection spreads to other body parts, including the bloodstream (sepsis), leading to widespread inflammation and damage to multiple organs.
Lung Abscesses: Abscesses are pockets of pus that form in the lungs, which are difficult to treat and require surgical intervention.
Pleural Effusion: Accumulated fluid in the pleural space (the area between the lungs and chest wall) compresses the lungs and makes breathing more difficult.
Bronchiectasis: Permanent dilation and damage to the bronchial tubes, leading to ongoing respiratory issues and a heightened susceptibility to infections.
Pulmonary Fibrosis: Scarring of lung tissue that reduces lung function and is typically irreversible, leading to chronic respiratory distress.
Hypoxia: Chronic oxygen deprivation leads to damage to vital organs, including the brain and heart, and is life-threatening.
Systemic Inflammatory Response Syndrome (SIRS): A severe inflammatory state affecting the whole body, which progresses to multiple organ failure and septic shock.

Is Pneumonia Fatal in Dogs?

Yes, pneumonia is fatal in dogs if not treated promptly. The severity and outcome of pneumonia depend on several factors, including the underlying cause, the dog’s overall health, age, and how quickly treatment is administered. “A single clone of Streptococcus equi subsp. zooepidemicus caused an acute, fatal, hemorrhagic pneumonia in over 1,000 mixed breed dogs in a single animal shelter,” Pesavento, P., Hurley, K., Bannasch, M., Artiushin, S., & Timoney, J. titled “A Clonal Outbreak of Acute Fatal Hemorrhagic Pneumonia in Intensively Housed (Shelter) Dogs Caused by Streptococcus equi subsp. Zooepidemicus,” 2008.

Factors influencing the prognosis of pneumonia include underlying diseases like diabetes or respiratory conditions, the dog's age, and the overall response to treatment.

Early diagnosis ensures a more favorable outcome, allowing for the immediate implementation of appropriate therapies to combat the infection. Hospitalization and intensive care are necessary to provide the dog with the best chance of recovery in some cases.

Can CBD Oil Help Dogs Pneumonia from Getting Worse?

Yes, CBD oil can help dogs with pneumonia from getting worse. The benefits of CBD oil in reducing inflammation are relevant to respiratory infections in canines, where inflammation influences the progression of pneumonia. “CBD demonstrated anti-inflammatory and immuno-modulating properties in dogs' immune cells using a canine ex vivo inflammatory model,” according to the study by Gugliandolo, E., Licata, P., Peritore, A., Siracusa, R., D’amico, R., Cordaro, M., Fusco, R., Impellizzeri, D., Paola, R., Cuzzocrea, S., Crupi, R., & Interlandi, C. titled “Effect of Cannabidiol (CBD) on Canine Inflammatory Response: An Ex Vivo Study on LPS Stimulated Whole Blood,” 2021.

The efficacy of Dog CBD oil in managing pneumonia in dogs is still being established, and its use as a treatment for respiratory infections is supplementary. CBD oil has anti-inflammatory properties that alleviate symptoms of inflammation, but its role in preventing pneumonia worsening requires further research.