# Pneumonia in Dogs: Symptoms, Causes, and Prognosis Pneumonia in dogs symptoms usually start with a soft or wet cough, faster breathing, and a drop in energy that does not improve with rest. The condition is an inflammation of the deep lung tissue that makes it hard for oxygen to reach the blood, so early recognition matters [1]. This article is educational and is not a substitute for veterinary diagnosis or treatment. ## Quick Answer - A wet, productive cough, rapid or labored breathing, fever, lethargy, and loss of appetite are the most common signs [1]. - The most frequent trigger is a viral infection of the lower airways that weakens the lungs and lets bacteria move in [2]. - Aspiration pneumonia happens when a dog inhales vomit, food, or improperly given medication, and it can follow persistent vomiting or esophageal problems [2][1]. - Diagnosis relies on history, a physical exam, chest X-rays, and lab work, with airway sampling when your vet needs to identify the exact organism [1]. - Most dogs improve with supportive care, oxygen when needed, and antibiotics if a bacterial infection is confirmed, but severe cases can be life threatening [1][3]. ## What Pneumonia Actually Is Pneumonia is inflammation of the pulmonary parenchyma, which means the small airways, the tissue between them, and the tiny air sacs called alveoli [1]. Those air sacs are where oxygen normally crosses into the bloodstream. When they fill with fluid, pus, or inflammatory cells, oxygen transfer drops and your dog has to work much harder to breathe [2][1]. This is different from a simple upper airway problem like kennel cough, which mostly affects the trachea and voice box. Pneumonia sits deeper in the chest, and that is why it tends to make dogs sicker. If your dog has a honking cough but is still eating and active, kennel cough is more likely. If the cough sounds wet and your dog is breathing fast at rest, pneumonia moves up the list. You can read more about the milder condition in [Kennel Cough Symptoms Dog](/knowledge/veterinary-medicine/symptom-guides/kennel-cough-symptoms-dog). ## Pneumonia in Dogs Symptoms: What You Will Notice Signs can build slowly over several days or appear within hours. The timeline often depends on the cause. ### Early signs - A cough that sounds wet, soft, or congested instead of dry and honking [1] - Tiring faster on walks or lagging behind on stairs - Reduced appetite and less interest in water - Mild fever and a general "off" attitude [1] ### Signs that mean the lungs are struggling - Breathing that is fast even when your dog is resting or asleep - Visible effort with each breath, including flaring nostrils or a pulled-in belly - Sitting with elbows out and neck stretched forward to open the chest - Lethargy that deepens through the day [1] - A blue or gray tint to the gums or tongue, which is an emergency ### The sound owners describe Owners often use words like "gurgly," "wet," or "rattly" for the pneumonia cough. Some dogs make a soft crackling sound you can hear when you put your ear near the chest. Others cough up a small amount of foam or fluid. A dry, goose-honk cough points more toward airway irritation than deep lung infection, and heart disease can also cause a chronic cough in older dogs. If you are trying to sort out the difference, [How to Tell If Your Dog's Cough Is Heart Disease or Something Else](/knowledge/veterinary-medicine/senior-and-chronic-care/dog-cough-heart-disease-or-other) walks through the clues. ### Symptoms timeline Many dogs show a cough and low energy for one to three days before breathing changes become obvious. Aspiration pneumonia can progress much faster, sometimes within 12 to 24 hours of a vomiting episode. Bacterial pneumonia often worsens over several days if it is not treated [1]. Any dog who is breathing hard at rest needs to be seen the same day, no matter how short the timeline seems. ## Pneumonia in Dogs Causes Pneumonia has many possible triggers, and sometimes more than one is involved at the same time. ### Viral infection The most common cause is a viral infection of the lower respiratory tract. Canine distemper virus, adenovirus types 1 and 2, canine influenza virus, and parainfluenza virus all damage the airways and make the lungs vulnerable to a secondary bacterial infection [2]. ### Bacteria Bacterial pneumonia is inflammation of the lower airways that is most often caused by bacterial infection [4]. One case series found Mycoplasma cynos as the sole pathogen in eight dogs with respiratory disease complex pneumonia, and Mycoplasma plus Bordetella bronchiseptica in five more [5]. Severe necrotizing pneumonia from E. coli has also been reported, though it is rare [6]. ### Aspiration Aspiration pneumonia results from inhaling vomit, regurgitated food, or improperly administered medications such as oil or barium, and it can also follow forced feeding [2]. Persistent vomiting and abnormal movement of the esophagus are common setups [2]. In a study of 30 dogs with aspiration pneumonia, all oropharyngeal swab cultures were positive and 16 of 30 airway lavage cultures were positive, which shows how tricky it is to pin down the true culprit from a simple swab [7]. ### Parasites, fungi, and protozoa Parasitic invasion of the bronchi can cause pneumonia, and fungal pneumonia does occur in dogs, though tuberculous pneumonia is uncommon [2]. A yeast called Candida glabrata has been described as a component of aspiration pneumonia in a dog with megaesophagus, and it can be resistant to common antifungal drugs [8]. ### Risk factors and breed predispositions Anything that affects swallowing, coughing, or airway clearance raises risk. Breed-related factors include primary ciliary dyskinesia and diseases causing laryngeal dysfunction and megaesophagus [4]. Irish Wolfhounds can develop a rhinitis and bronchopneumonia syndrome as puppies and recurrent bacterial pneumonia as adults. Cavalier King Charles Spaniels and Miniature Dachshunds have a breed-related predisposition to immune deficit and Pneumocystis pneumonia [4]. For a deeper look at how these pathways work, see [How Does A Dog Get Pneumonia](/knowledge/veterinary-medicine/clinical-methods/how-does-a-dog-get-pneumonia). | Cause | Typical trigger | What owners often see first | |---|---|---| | Viral | Distemper, adenovirus, influenza, parainfluenza [2] | Dry cough that turns wet, low energy | | Bacterial | Secondary infection or primary bacteria such as Mycoplasma [4][5] | Fever, wet cough, poor appetite | | Aspiration | Vomiting, regurgitation, forced feeding, misplaced medication [2] | Cough right after eating or vomiting | | Parasitic or fungal | Bronchial parasites, fungal organisms, Candida [2][8] | Slow, lingering cough that resists treatment | ## How Pneumonia Is Diagnosed Your veterinarian starts with history and a physical exam, listening to the chest and checking breathing rate, gum color, and temperature. Diagnosis is based on history, clinical signs, thoracic radiographs, and other laboratory testing [1]. Chest X-rays are the main imaging step. They show where the lung pattern is abnormal and how much of the lung is involved. Bloodwork helps assess oxygen status and inflammation. In one study of dogs with bacterial pneumonia, arterial blood analysis showed lower oxyhemoglobin and higher deoxyhemoglobin levels compared with dogs without respiratory disease, which reflects poorer oxygen delivery [3]. When the cause is unclear or the dog is not improving, your vet may collect a sample from the lower airway, often by bronchoalveolar lavage, and send it for culture. This matters because surface swabs do not reliably match what is growing deep in the lungs [7]. C-reactive protein, a marker of inflammation, has shown promise as a way to gauge pneumonia severity, with moderate correlation to radiographic severity scores in one study of dogs with tick paralysis [9]. ## Treatment Options Treatment is supportive care, including oxygen, plus antimicrobial therapy if it is indicated [1]. - **Oxygen support.** Dogs with low blood oxygen may need an oxygen cage, nasal cannula, or flow-by oxygen. - **Antibiotics.** Your veterinarian chooses the drug and calculates the dose from your dog's weight, the suspected organism, and overall health. Duration is often two weeks or longer for bacterial pneumonia [5]. - **Antifungals or antiparasitics.** Used when a fungal or parasitic cause is identified [2][8]. - **Airway clearance.** Coupage (gentle chest tapping), controlled activity, and keeping your dog hydrated help move secretions. - **Fluid and nutrition support.** Dogs who will not eat may need assisted feeding, and vomiting or regurgitation must be controlled to prevent repeat aspiration [2]. - **Surgery in rare cases.** A dog with necrotizing E. coli pneumonia and secondary pneumothorax needed a median sternotomy and removal of part of a lung lobe after antibiotics alone were not enough. That dog survived to discharge [6]. Never give human cough suppressants or leftover antibiotics. Some of these drugs are toxic to dogs, and the wrong antibiotic can delay the right treatment. ## Recovery, Outlook, and Long-Term Management Prognosis depends on the cause, how much lung is involved, and how quickly treatment starts. Dogs with mild bacterial pneumonia often improve within a few days of starting the right antibiotic, though the cough can linger for a week or more. Dogs who need oxygen or have a large portion of lung affected face a more guarded outlook. In one study of 30 dogs with bacterial pneumonia, some did not survive, which shows this is a serious disease instead of a minor chest cold [3]. If your dog develops signs of whole-body inflammation or organ stress during treatment, the situation becomes more serious. [Sepsis in Dogs: Prognostic Indicators and Survival Rates](/knowledge/veterinary-medicine/emergency-critical-care/sepsis-dogs-prognostic-indicators-survival-rates) explains what those warning signs look like. Long-term management focuses on the underlying problem. Dogs with megaesophagus, laryngeal disease, or ciliary dyskinesia may need lifelong changes to how they eat and drink, plus regular checkups [4]. Some dogs need repeat X-rays to confirm the lungs are clearing. A cough that returns after treatment should always be rechecked. ## Prevention - Keep vaccinations current for distemper, adenovirus, parainfluenza, and influenza, since these viruses set the stage for pneumonia [2]. - Feed upright and hold your dog steady if they regurgitate, and ask your vet about feeding position for megaesophagus. - Never force food, oil, or medication into a struggling dog's mouth [2]. - Treat vomiting and regurgitation promptly instead of waiting it out. - Avoid close contact with coughing dogs at parks, daycares, and boarding facilities. - Ask your vet about airway clearance routines if your dog has a chronic swallowing or coughing condition. ## Limitations and When to Contact a Veterinarian This article cannot tell you what is wrong with your individual dog. Only a veterinarian who examines your dog can do that. **Call an emergency clinic now if your dog:** - Breathes with obvious effort at rest, or you can see the belly pulling in with each breath - Has blue, gray, or white gums - Collapses, cannot stand, or seems to be suffocating - Breathes rapidly right after vomiting or regurgitating **Call your veterinarian the same day if your dog:** - Has a new wet cough - Has a fever, is not eating, or is much sleepier than usual - Has been coughing for more than two or three days - Is a breed with a known risk, such as an Irish Wolfhound, Cavalier King Charles Spaniel, or Miniature Dachshund [4] **Schedule a routine visit if your dog:** - Has a mild cough but is eating, drinking, and active normally - Has a cough that keeps coming back after treatment ## Frequently Asked Questions ### Can pneumonia in dogs go away on its own? Mild cases sometimes improve with rest and supportive care, but bacterial pneumonia usually needs antibiotics and can worsen quickly without them [1]. Waiting too long lets the infection spread through more of the lung. Any dog with fast breathing or a wet cough should be seen instead of watched at home. ### Is pneumonia contagious to other dogs? The viruses and bacteria that cause pneumonia can pass between dogs, especially in crowded settings like shelters and daycares [2][5]. The pneumonia itself is not a single contagious disease, but the organisms behind it often are. Keep a coughing dog away from others until your veterinarian clears them. ### How long does pneumonia last in dogs? Many dogs start improving within a few days of correct treatment, and antibiotics are often prescribed for two weeks or longer [5]. The cough may last longer than the fever and lethargy. Follow-up X-rays are sometimes needed to confirm the lungs have cleared. ### Can I catch pneumonia from my dog? The specific organisms involved are generally not passed from dogs to people in normal household contact. Some bacteria, such as Bordetella bronchiseptica, have rarely been linked to illness in people with severely weakened immune systems [5]. If someone in your home is immunocompromised, mention it to your veterinarian. ### What is the survival rate for dogs with pneumonia? There is no single number, because survival depends on the cause, the amount of lung affected, and how quickly treatment starts. One study of dogs with bacterial pneumonia reported that some did not survive, which confirms the disease can be fatal [3]. Dogs treated early, especially those who do not need oxygen, generally do better. ## Related Articles - [How Does A Dog Get Pneumonia](/knowledge/veterinary-medicine/clinical-methods/how-does-a-dog-get-pneumonia) - [Sepsis in Dogs: Prognostic Indicators and Survival Rates](/knowledge/veterinary-medicine/emergency-critical-care/sepsis-dogs-prognostic-indicators-survival-rates) - [Kennel Cough Symptoms Dog](/knowledge/veterinary-medicine/symptom-guides/kennel-cough-symptoms-dog) - [Dog Kennel Cough Symptoms And Treatment](/knowledge/veterinary-medicine/symptom-guides/dog-kennel-cough-symptoms-and-treatment) - [How to Tell If Your Dog's Cough Is Heart Disease or Something Else](/knowledge/veterinary-medicine/senior-and-chronic-care/dog-cough-heart-disease-or-other) - [Canine Liver Disease: Symptoms, Diagnosis, Staging & Treatment](/knowledge/veterinary-medicine/internal-medicine/canine-liver-disease) ## References 1. [Pneumonia in Dogs and Cats - Respiratory System](https://www.merckvetmanual.com/respiratory-system/respiratory-diseases-of-small-animals/pneumonia-in-dogs-and-cats). Merck Veterinary Manual. 2. [Pneumonia in Dogs - Dog Owners](https://www.merckvetmanual.com/dog-owners/lung-and-airway-disorders-of-dogs/pneumonia-in-dogs). Merck Veterinary Manual. 3. [Retrospective analysis of carboxyhemoglobin and methemoglobin levels and their association with pneumonia severity in dogs](https://pubmed.ncbi.nlm.nih.gov/42314230/). Research in veterinary science, 2026. 4. [Breed Specific Pneumonia](https://pubmed.ncbi.nlm.nih.gov/42062104/). The Veterinary clinics of North America. Small animal practice, 2026. 5. [Mycoplasma cynos-Associated Canine Infectious Respiratory Disease Complex Pneumonia in 13 Dogs](https://pubmed.ncbi.nlm.nih.gov/41178398/). Journal of veterinary emergency and critical care (San Antonio, Tex. : 2001), 2025. 6. [Necrotizing E. coli pneumonia with subsequent pneumothorax in a dog: a case report](https://pubmed.ncbi.nlm.nih.gov/41049142/). Frontiers in veterinary science, 2025. 7. [Diagnostic limitations of oropharyngeal swab cultures and inconsistent presence of secondary bacterial infection in canine aspiration pneumonia](https://pubmed.ncbi.nlm.nih.gov/42019547/). Journal of the American Veterinary Medical Association, 2026. 8. [Candida glabrata (Nakaseomyces glabratus) as a component of aspiration pneumonia in a dog with megaesophagus](https://pubmed.ncbi.nlm.nih.gov/41716509/). The Canadian veterinary journal = La revue veterinaire canadienne, 2026. 9. [A prospective cohort study of C-reactive protein as a marker of aspiration pneumonia in canine tick paralysis (Ixodes holocyclus)](https://pubmed.ncbi.nlm.nih.gov/41062098/). Australian veterinary journal, 2026. ## Further Reading - [Merck Veterinary Manual: Dog Owners](https://www.merckvetmanual.com/dog-owners) - [Cornell Richard P. Riney Canine Health Center: Canine Health Information](https://www.vet.cornell.edu/departments-centers-and-institutes/riney-canine-health-center/canine-health-information) - [American Veterinary Medical Association: Pet Care](https://www.avma.org/resources-tools/pet-owners/petcare)