Pneumonia in Dogs
Pneumonia is an inflammation of the lungs, usually caused by infection, that can range from a mild illness to a life-threatening emergency. Unlike a simple chest cough, pneumonia involves the actual lung tissue — the tiny air sacs (alveoli) fill with fluid, pus, or inflammatory material, making it hard for oxygen to pass into the bloodstream. Understanding the different types of pneumonia and knowing when your dog needs urgent veterinary attention could save their life.
Types of Pneumonia in Dogs
Bacterial Pneumonia
Bacterial pneumonia is the most common form in dogs. It can develop as a primary infection or as a secondary complication following a viral illness such as canine distemper or influenza. The bacteria most frequently involved include Bordetella bronchiseptica (one of the agents behind kennel cough), Streptococcus, Pasteurella, and Escherichia coli. Dogs that have weakened immune systems — due to illness, medication, or age — are at greater risk.
Aspiration Pneumonia
Aspiration pneumonia occurs when foreign material — food, water, vomit, or stomach acid — is accidentally inhaled into the lungs. This sets off a severe inflammatory reaction and opens the door to secondary bacterial infection. It is a particularly dangerous condition because it can worsen very rapidly.
Certain dogs face a significantly higher risk of aspiration:
- Brachycephalic (flat-faced) breeds such as Bulldogs, Pugs, and French Bulldogs, whose anatomy affects swallowing coordination
- Dogs with megaoesophagus — an enlarged, poorly functioning oesophagus that does not move food into the stomach efficiently, leading to regurgitation
- Dogs with laryngeal paralysis, which reduces airway protection during swallowing
- Dogs recovering from anaesthesia or those that have experienced vomiting during a seizure
- Dogs being hand-fed or syringe-fed too quickly
Recognising the Symptoms
The signs of pneumonia in dogs can develop over several days or come on suddenly. Key symptoms include:
- A persistent, productive cough that may bring up mucus or phlegm
- Rapid or laboured breathing, often with the dog stretching their neck forward
- Fever — a temperature above 39.2 degrees Celsius
- Lethargy and reluctance to exercise
- Loss of appetite
- Nasal discharge, often greenish or yellowish
- Dehydration
- Blue or grey gums in severe cases, indicating dangerously low oxygen
Some dogs, particularly those with mild early-stage pneumonia, may simply seem "off" — quieter than normal, less interested in food, and slightly off their usual routines. Do not wait for symptoms to worsen before contacting your vet.
How Vets Diagnose Pneumonia
Clinical Examination and History
Your vet will listen carefully to your dog's chest with a stethoscope. Crackles and harsh breath sounds in specific lung regions are characteristic of pneumonia. They will also ask about your dog's history — recent illness, vomiting, regurgitation, breed, and any medications.
Chest X-rays
Radiographs of the chest are essential. Pneumonia typically shows as areas of increased density — known as consolidation — within the lung tissue. The pattern and location of these changes can help distinguish bacterial pneumonia from aspiration pneumonia, as aspiration tends to affect the dependent lobes (those nearest the ground when the dog is lying down).
Tracheal Wash and Culture
To identify the specific bacteria causing the infection, vets often perform a tracheal wash (also called a transtracheal wash). A small amount of sterile saline is flushed into the trachea and retrieved, collecting a sample of material from the airways. This sample is sent for culture and sensitivity testing, which identifies the bacteria present and, crucially, which antibiotics will be most effective against it. Starting treatment with the wrong antibiotic wastes precious time, so this test is very valuable.
Blood Tests
A full blood count often reveals an elevated white cell count (leucocytosis), indicating active infection. Blood gas analysis may be performed in severe cases to measure oxygen levels in the bloodstream.
Treatment
Antibiotics
Antibiotic treatment is the cornerstone of bacterial and aspiration pneumonia management. Where possible, the choice of antibiotic is guided by culture results. Broad-spectrum antibiotics are started immediately while waiting for those results. Treatment typically lasts three to six weeks, and it is vital to complete the full course even if your dog seems to recover quickly. Stopping early risks a relapse and antibiotic resistance.
Hospitalisation and Oxygen Therapy
Dogs with moderate to severe pneumonia often require a stay in a veterinary hospital for intravenous antibiotics, intravenous fluids to combat dehydration, and supplementary oxygen therapy. Oxygen cages or flow-by oxygen can make a significant difference to a struggling dog's comfort and recovery speed.
Nebulisation
Nebulisation involves delivering a fine mist of saline — sometimes with added medications — directly into the respiratory tract. This helps to loosen and thin mucus, making it easier to clear. It is used both in hospital and sometimes continued at home with a rented or purchased nebuliser unit.
Coupage Physiotherapy
Coupage is a physiotherapy technique in which the owner or a nurse gently cups their hand and taps rhythmically on the dog's chest wall. This vibration helps to dislodge mucus from the smaller airways so it can be coughed up. Your vet or nurse will show you the correct technique if coupage is recommended for your dog's home care. It is typically performed for several minutes, several times a day, ideally after nebulisation when mucus is already loosened.
Recovery and Monitoring
Recovery from pneumonia takes time. Even after antibiotics have cleared the infection, inflamed lung tissue needs weeks to heal fully. Repeat chest X-rays — usually at two to four week intervals — are used to monitor progress and confirm that the pneumonia is resolving. Do not be surprised if your dog remains quieter than usual for several weeks.
At home during recovery, keep your dog warm and dry, offer small, frequent meals, and avoid vigorous exercise until your vet gives the all-clear. If your dog has an underlying condition such as megaoesophagus, your vet will advise on feeding position (usually elevated) to reduce the risk of further aspiration.
Contact your vet immediately if your dog's breathing worsens, their gums change colour, or their temperature rises again during recovery. Pneumonia can relapse, and early intervention makes a significant difference to the outcome.