What is Dog Pneumonia?
Dog pneumonia is characterized by irritation and inflammation in the lungs, leading to the accumulation of fluid in the air sacs. This condition hampers the normal exchange of oxygen and carbon dioxide within the lungs, resulting in breathing difficulties. Pneumonia in dogs can stem from various causes, including:
- Bacteria
- Viruses
- Fungal organisms
- Parasites
- Immune-mediated factors
- Inhalation of stomach contents, food, chemicals, fluids, or foreign materials
- Inhalation of chemicals or smoke
The severity of pneumonia varies, ranging from mild symptoms affecting small lung areas to severe respiratory distress and impaired breathing. Many cases of pneumonia necessitate immediate veterinary attention and should be treated as emergencies.
Symptoms
Symptoms of dog pneumonia encompass a spectrum from mild to severe. The most prevalent signs include:
- Coughing
- Difficulty breathing
- Nasal discharge
- Wheezing
- Fever
- Lethargy
- Respiratory distress
- Bluish gums, in severe instances
Causes
The causes of dog pneumonia are diverse, and it’s common for a dog to experience multiple types of pneumonia simultaneously. This occurrence is most frequent with secondary bacterial infections.
Aspiration Pneumonia
Aspiration pneumonia arises when a dog inhales substances such as food or vomit. It stands as one of the more prevalent forms of pneumonia. The inhaled food material obstructs air spaces and triggers inflammation within the lungs. Stomach acids can also directly harm lung cells. These factors collectively create an ideal environment for a secondary bacterial infection. Certain animals face a heightened risk of developing aspiration pneumonia due to factors such as:
- Impairment of the larynx
- Under sedation or anesthesia
- Neurological disorders
- Medically necessitated force-feeding
- Proneness to vomiting or regurgitation
- Brachycephalic breeds (Pugs, Bulldogs, Boston Terriers, etc.)
Bacterial Pneumonia
Bacterial pneumonia is a prevalent condition in dogs. Bacteria typically infiltrate the lungs through aspiration or inhalation, seldom spreading via the bloodstream. Most healthy adult dogs do not develop primary bacterial pneumonia. However, puppies, elderly dogs, and those with weakened immune systems are more vulnerable. Usually, bacterial pneumonia serves as a secondary condition or collaborates with larger respiratory issues involving multiple bacteria and viruses. Common bacteria detected in dogs with pneumonia include:
- Bordetella
- Mycoplasma
- Yersinia
- Streptococcus
- E. coli
- Klebsiella
- Pseudomonas
- Enterococcus
- Pasteurella
- Bacillus
- Fusobacterium
Several factors contribute to a dog contracting bacterial pneumonia. Dogs may be at risk due to the following conditions:
- Viral or fungal pneumonia
- Immunosuppression from medications or other illnesses
- Cancer
- Extended surgical procedures
- Airway blockage or structural abnormalities
- Vomiting and subsequent aspiration
- Metabolic disorders
- Altered mental status, such as seizures
- Inhalation of foreign objects
- Lung cell damage from smoke, chemical inhalation, or drowning
- Sepsis
Viral Pneumonia
Viral pneumonia can encompass infections involving multiple viruses and may coincide with bacterial organisms. They primarily spread through inhalation and are often highly contagious to other dogs. Dogs in shelters, long-term boarding facilities, daycare centers, or dog parks may face an elevated risk of viral pneumonia. Common organisms associated with viral pneumonia include:
- Canine influenza
- Canine distemper
- Canine adenovirus-2
- Canine herpesvirus
- Canine parainfluenza virus
Fungal Pneumonia
Fungal pneumonia is prevalent in the South and Southwest regions of the country. Dogs contract fungal infections by inhaling fungus from contaminated soil or plants. Pets living near construction sites or new homes may face an even greater risk. Common fungal pathogens include:
- Blastomyces
- Histoplasma
Parasitic and Protozoal Pneumonia
Parasitic and protozoal pneumonia arises when living parasites reside and reproduce in a dog’s lungs. Dogs can contract parasites through contaminated feces and, in the instance of heartworm, via insect vectors such as mosquitoes. This form of pneumonia is rare in dogs and encompasses:
- Neospora
- Toxoplasma
Eosinophilic or Allergic Pneumonia
Eosinophilic pneumonia develops when the dog’s immune system prompts a type of white blood cell (eosinophils) to inundate the lungs. Respiratory tract irritants such as spores, pollen, or insect antigens can trigger this immune response.
Inhalation Pneumonia
Inhalation pneumonia can arise from inhaling noxious fumes or gases, such as chemicals and smoke. Toxic particles disrupt the body’s capacity to process oxygen normally, while also impacting the usual mucus and clearance functions within the lungs.
Diagnosis
Veterinarians employ various diagnostic tests to identify pneumonia in dogs. Typically, they begin by auscultating the lungs using a stethoscope. Signs of fluid in the chest may manifest as crackles, wheezes, or pops, although sometimes the lungs may be quieter than usual. If coughing or breathing difficulties are present, veterinarians may suggest further diagnostic evaluations.
Radiography
Veterinarians utilize chest radiographs, or X-rays, to diagnose pneumonia. Specialized 3-view X-rays help assess its severity. On X-rays, fluid and inflammation appear distinct from air, displaying gray, patchy, or hazy patterns. Pneumonia can affect one lung lobe or multiple lobes, and fluid accumulation may cause lung collapse.
Blood Chemistry and Complete Blood Count (CBC)
A complete blood count (CBC) may reveal signs of inflammation and infection. Blood chemistry may indicate sepsis in severe cases, along with predisposing factors or reasons for vomiting.
Pulse Oximetry and Blood Gas Analysis
Pulse oximetry and blood gas analysis determine if the patient is receiving adequate oxygen and confirm respiratory dysfunction. These tests are crucial for follow-up and treatment monitoring. Pulse oximetry uses infrared light to non-invasively measure oxygen levels in capillaries. Blood gas analysis involves collecting blood via a special catheter for analysis of oxygen, carbon dioxide, and pH levels.
Culture and Cytology
Dogs with pneumonia may undergo procedures like transtracheal washes, bronchoalveolar lavage, and bronchoscopy to obtain lung fluid samples. Special instruments are used to explore the respiratory tract and collect pure samples. Veterinarians examine samples under a microscope for cells and pathogens. Cultured samples help identify specific bacterial pathogens for targeted antibiotic therapy.
Other Tests
Veterinarians may employ advanced imaging like MRI or CT scans to assess pneumonia extent and other risk factors. Tests for infectious agents and parasites, including PCR and serology, may also be used. Blood cultures are rarely necessary, as local cultures generally provide accurate results.
Treatment
Treatment for dog pneumonia varies depending on the type of pneumonia and underlying conditions. The severity of the disease also determines the intensity of treatment. Mild cases may be managed at home with medications, rest, and attentive care. Moderate to severe cases often necessitate hospitalization at emergency facilities with round-the-clock nursing care and specialized equipment.
Antibiotics
Veterinarians prescribe antibiotics for dogs with primary or secondary bacterial pneumonia. Common antibiotics include Doxycycline, Fluoroquinolone, and Amoxicillin-clavulanic Acid. Treatment duration is typically prolonged, sometimes exceeding a month. Regular check-ups help determine the necessary duration of antibiotic therapy.
Oxygen Therapy
Animals unable to oxygenate adequately on room air receive supplemental oxygen. This can be administered via a nasal or face mask, although veterinarians often prefer using an oxygen cage. An oxygen cage offers a controlled environment where oxygen levels can be adjusted from room air to 100 percent oxygen. It’s a minimally stressful method for providing oxygen to dogs in respiratory distress and indicates the severity of the dog’s illness.
Fluid Therapy
Dehydrated dogs with pneumonia require intravenous catheters and fluid therapy to restore hydration. Dehydration compromises respiratory clearance and function, making fluid therapy crucial in pneumonia cases.
Nebulization and Coupage
Nebulizers generate a fine mist to increase airway humidity, akin to the moist environment in a bathroom during a shower. Saline is commonly used to hydrate the airway, sometimes supplemented with antibiotics. Following nebulization, dogs may undergo coupage, involving gentle tapping around the chest to break apart and clear mucus and trapped cells in the airways.
Ventilation
Severe pneumonia cases may necessitate full sedation and mechanical ventilation to support breathing. This intervention is reserved for dogs unresponsive to initial oxygen therapy or those minimally responsive, typically requiring intensive care unit management.
Living and Management
During the acute phase of recovery, X-rays are typically conducted every two to five days, followed by subsequent assessments every one to two weeks until complete resolution. After full recovery, periodic X-rays should be taken every few months to monitor for any recurrence. Within the first two weeks post-pneumonia episode, veterinarians recommend rechecking the exam and bloodwork.
It’s generally advised to continue treatment for at least a week after the clinical signs and X-ray evidence have resolved. Veterinarians typically do not suggest cough suppressants for dogs recovering from pneumonia, as coughing aids in removing infection and fluid from the airways naturally.
Dog Pneumonia FAQs
Is dog pneumonia contagious?
Certain types of canine pneumonia, such as those involving viral or bacterial components, can be contagious to other dogs.
What is the survival rate for dogs with pneumonia?
The prognosis for canine pneumonia is generally favorable, especially with prompt and aggressive veterinary treatment. Studies indicate that approximately 77 to 94 percent of patients with bacterial pneumonia survive until discharge.
How can I tell if my dog has pneumonia?
Dogs afflicted with pneumonia typically exhibit signs of severe illness, including lethargy and abnormal behavior. If you notice changes in your pet’s breathing or overall condition, it’s important to contact your veterinarian or seek immediate treatment at an emergency hospital.