Pneumonia In Dogs – Symptoms, Causes, & Treatments

Pneumonia has been described as an infection of the pulmonary parenchyma in one or both lungs and the alveoli (air sacs) become inflamed and fill up with fluid or pus. This is not a single condition as the term ‘pneumonia’ is considered a comprehensive term for various syndromes caused by several pathogens resulting in wide-ranging manifestations and sequelae.

The term "pneumonia" is coined from the Greek word ‘pneúmōn’, which means "lung," so the word "pneumonia" means "lung disease."

There are many different types of pneumonia. Based on etiology, it can be classified as infectious and non-infectious. Most dogs can get two types of pneumonia: bacterial (infectious) and aspiration pneumonia (non-infectious type).

The most common type of pneumonia in dogs is ‘Infectious pneumonia’. The condition is mostly caused by a bacterial, viral, or fungal infection in your dog’s airways. On the other hand, aspiration pneumonia (inhalation pneumonia) is caused by a secondary infection that is caused by lung inflammation and over-accumulation of mucus.

Infectious Pneumonia:

• Acute onset of nonproductive cough.
• Coughing
• Breathing difficulties / Nasal whistling
• Runny nose
• Wheezing
• Pyrexia
• Lethargy
• Decreased exercise tolerance.
• Dehydration
• Weight loss / Anorexia / Loss of appetite

In addition to these, Non-infectious pneumonia may also cause other symptoms such as:

• Bluish skin
• Frequent regurgitation
• Difficulty swallowing
• Irritable / Aggressive

Severe Cases:

• Dogs try to clear their throat or spit up or gag, often mistaken as vomiting.
• Bronchopneumonia
• Tachypnea
• Respiratory distress

The specific treatment for Pneumonia in dogs depends on the results type of infection and the severity of signs.

• Intravenous fluid and nutritional therapy may be given to help your dog if it becomes severely dehydrated.
• For respiratory distress is apparent, oxygen therapy should be given.
• Your vet keeps your dog hydrated by administering electrolytes through an intravenous (IV) fluid therapy.
• Immunosuppressive or anti-inflammatory medications.
• Broad-spectrum Antibiotics: Doxycycline or amoxicillin (Fluoroquinolones, Trimethoprim/sulfa).
• Severe Pneumonia: Ticarcillin in combination with clavulanate.
• Cough suppressants (Balminil, Benylin, Delsym, Robitussin)
• Endotracheal Lavage - Perform the wash through a sterile endotracheal tube for small and toy breeds of dogs.

• Keep the affected dog in isolation and after they are deemed recovered for at least a few more weeks.
• During their recovery, provide plenty of freshwater near them to help keep them hydrated.
• It’s good to give a steam treatment by running a hot shower while you are having a hot shower in the bathroom.

Considering the risk factors facing your pet, check with your vet how often your dog should get - vaccines for kennel cough are available.

• Bordetella Vaccine:
  • First Vax (6-8 weeks).
  • Second Vaccination (10-12 weeks).
  • Intranasal and oral kennel cough shots - every 1 year.
  • The booster shots are effective for one year.
• Distemper Vaccine (DHPP or DAPP vaccines):
  • Puppies at 6 - 8 weeks old and then every 2 - 3 to four weeks until 16 weeks old.
  • They may need another booster every 1 to 3 years for the rest of their lives. However, a specific vaccine schedule may be recommended by your vet based on how common the distemper is in your area.

Young Dogs, Senior Dogs.

There is no breed disposition.

In general, the below-mentioned dogs are over-represented:

• Hounds
• Large mixed-breeds
• Working or sporting breed dogs
• Immunocompromised dogs

1. Causes:

A. Infectious Pneumonia:

• Bacterial Pneumonia - Including Staphylococcus, Streptococcus, E.coli, Bordetella bronchiseptica, Pasteurella multocida, Pseudomonas aeruginosa, and Klebsiella pneumonia.
• Fungal Pneumonia - Histoplasma capsulatum, Blastomyces dermatitidis, Cryptococcusneoformans, and Coccidioides immitis.
• Protozoal Pneumonia - Toxoplasma gondiiand Neospora caninum.
• Viral Pneumonia - Canine coronavirus, canine distemper virus, canine adenovirus-2, canine influenza virus (H3N8), and canine parainfluenza virus.
• Parasites - Ancylostoma and Toxocara (during larval migration), Paragonimus kellicotti, milksi, and Filaroides hirthi.
• Rickettsia rickettsii - Acute interstitial pneumonia caused by Rocky Mountain spotted fever.

B. Non-infectious Pneumonia:

• Aspiration Pneumonia - also called Chemical pneumonitis, is caused by inhaling food, liquid, saliva, and vomit.
• Inhalation of foreign bodies.
• With certain types of ILDs.

2. Types:

A. By Clinical Symptoms:

Acute vs. Chronic Pneumonia:

Acute Pneumonia: Onset of symptoms < 3 weeks of duration.

Chronic Pneumonia: Longer duration pneumonia. They are either non-infectious or infectious (fungal or mixed bacterial infections).

B. Site Acquired:

Community-acquired: Pneumonia acquired by a dog that is not recently visited a vet clinic.

Hospital-acquired: Pneumonia acquired during or after visiting the vet clinic for another illness or procedure.

C. Location of lung affected:

Lobar Pneumonia: Single lobe/section of lungs.

Multilobar Pneumonia: Several lobes.

Bronchial Pneumonia: Bronchioles.

Interstitial Pneumonia: Areas in between the alveoli.

3. Morbidity:

Pneumonia Vs Bronchitis:

Bronchitis is an inflammation of the bronchial tubes (called bronchioles) that carry air to the lungs while pneumonia affects the tiny air sacs (alveoli) where oxygen passes into your bloodstream.

Pneumonia Vs Pulmonary Edema Vs Pleural Effusion:

• Pulmonary Edema - Fluid buildup inside the lungs.
• Pleural Effusion - Fluid collects in the layers of tissue that line the outside of the lungs and the inside of the chest.
• Pneumonia - Fluid buildup in the tiny air sacs in your lungs and it’s caused by an infection.

4. Mortality:

Young dogs and immunocompromised dogs have the highest mortality rate (usually it ranges from 1% to 5%).

5. Diagnosis:

• X-rays of the chest and lungs.
• Complete Blood Count (CBC), Blood Culture.
• CT Scan
• Pleural Fluid Culture

6. Differential Diagnosis:

• Chronic obstructive pulmonary disease (COPD).
• Heart disease-causing pulmonary edema.
• Lung Cancer
• Cystic Fibrosis

7. Prognosis:

Pneumonia is a serious condition that may turn life-threatening when left untreated. Most dogs recover well with proper treatment. There is a danger the condition can reoccur and it is called Recurring pneumonia. However, this happens if the underlying cause is not correctly identified and treated.

Infectious pneumonia (such as bacterial pneumonia) has a good prognosis. Moreover, bacterial pneumonia may be associated with two secondary conditions: hypoxemia and sepsis. When proper medical attention is not provided, this may result in increased fatalities.

Contact your vet right away, if you notice any of the following:

• Breathing difficulties / Nasal whistling
• Frequent regurgitation

• Low-carb dog food / Peas, sweet potatoes, squash, yams, pumpkin, etc.
• Fresh, lean protein (Lean ground beef, White-meat skinless chicken, or turkey).
• Antioxidants - Blueberries, blackberries, Steamed broccoli, spinach, cooked yellow squash, kale, and green beans.
• Iron: Lean meats like ground beef and lamb, fish, such as sardines and salmon, pumpkin, carrots, and leafy greens.
• Vitamin C and Bioflavonoids: Brussel sprouts, spinach, broccoli, kale, pineapple, papaya, strawberries, etc.

For pets with pneumonia, early diagnosis with prompt treatment, as well as routine follow-up examinations is of paramount importance to ensure there are no secondary infections.