Pneumonia in Cats – Causes, Sympoms and Treatment

Pneumonia at a glance

  • Pneumonia is an infection of the lung sacs within the lungs caused by bacterial, viral, fungal infection of aspiration (inhalation of food, water or medicine).
  • Symptoms of pneumonia include fever, rattling breathing, lethargy, rapid breathing, blue gums, loss of appetite.
  • Diagnosis is based on symptoms as well as lung aspiration, tracheal wash, and imaging studies.
  • Treatment may include antibiotics, anti-virals, anti-fungals and supportive care.

Pneumonia in cats

What is pneumonia?

Pneumonia is an infectious/inflammatory disorder of the lung parenchyma. The lungs are filled with thousands of tiny bronchi, which end in smaller sacs known as alveoli which contain tiny blood vessels. Oxygen is added to the blood and carbon dioxide removed via the alveoli. Pneumonia causes these alveoli to fill with pus and fluids which affect the lung’s ability to exchange gases.

There are several types of pneumonia, some of which include:

  • Bacterial – Many types of bacteria can cause pneumonia in cats including Streptococcus, Chlamydia felis, Yersinia Pestis (the bacteria responsible for pneumonic plague), Pasteurella multocida, Staphylococcus, Bordetella and more. Often it develops secondary to a viral infection or aspiration. This type of bacteria may develop as a secondary to a viral infection when the cat’s natural defenses are already weakened. It is also possible for bacterial pneumonia to originate from elsewhere in the body.
  • Viral – Upper respiratory infections are common in cats, particularly kittens and stressed cats in crowded environments (such as shelters). Feline calicivirus and herpesvirus are the most common causes. Inflammation in the lungs can lead to secondary bacterial infection. FIV and FeLV both lead to a decreased immune system, which can increase the incidence of pneumonia due to infectious agents.
  • Fungal – Mycotic (fungal pneumonia) infections are relatively rare in cats. Cryptococcosis, blastomycosis, aspergillosis and histoplasmosis. Once again, a cat with FIV or FeLV may be at greater risk due to their weakened immune system which allows for infection to take hold.
  • Parasitic – This form of pneumonia is rare in cats and almost always occurs in either young kittens or immunocompromised cats. Parasites which can cause pneumonia include lungworm, toxoplasmosis, liver flukes, roundworms.
  • Aspiration – Inhalation of gastric contents during vomiting or administration of medications. Cats are particularly vulnerable to aspiration pneumonia when given mineral oils to treat hairballs or have a recent history of general anesthesia. Cats who are chronic vomiters and cats with a cleft palate are also at greater risk of developing aspiration pneumonia. Inhalation of a foreign substance such as a grass awn can lead to inflammation of the lungs as well as bacterial infection.

What are the symptoms of pneumonia in cats?

The most common symptom of pneumonia is a cough which is moist and dyspnea (difficulty breathing). Other symptoms include:

There may be additional symptoms relating to the underlying cause if one is present. For example draining skin lesions and ocular manifestations in cats who have systemic fungal infections.

Not all cats with pneumonia will display respiratory signs and some cats may only be found to have pneumonia when it shows up on an x-ray.

How is pneumonia diagnosed?

Your veterinarian will perform a complete physical examination of your cat and obtain a medical history from you. He will listen to the chest with a stethoscope which will reveal increased and harsh lung sounds. Symptoms may be acute or chronic depending on the underlying cause.  He may need to perform the following tests to determine if your cat has pneumonia:

  • Routine blood tests including complete blood count and biochemical profile. Increased white blood cells are common with bacterial and fungal pneumonia. Cats with FIV may have anemia, decreased white blood cells and lymphocytes. These tests can also give your veterinarian a picture of your cat’s overall health prior to commencing treatment.
  • Lung aspiration – A needle is pushed through the chest into the lungs and lung cells are aspirated into the syringe. These cells are then studied under a microscope for the presence of infectious organisms.
  • Tracheal wash – This is performed in order to obtain cells from the trachea which can be cultured to analyse and determine the particular organism involved.
  • Chest x-ray – This will confirm that your cat has pneumonia and look for inhaled foreign objects (if one is suspected).
  • Blood gas evaluation to measure the levels of oxygen in the cat’s blood.

As well as diagnosing pneumonia, your veterinarian will want to look for an underlying cause:

  • Fecal examination to look for the presence of parasites.
  • Blood tests to check for FIV, FeLV, toxoplasmosis.
  • A culture of nasal or eye discharges to check for Y. pestis (in affected areas).

How is pneumonia treated?

Your cat may have to stay at in hospital for treatment if he is severely ill, milder cases may be treated at home. Treatment will depend on the cause of pneumonia and may include:

  • Antibiotics will be prescribed to treat a bacterial infection or toxoplasmosis. The appropriate antibiotic will be selected based on bacterial cultures and antibiotic sensitivity testing.
  • Mycotic (fungal) pneumonia typically requires long-term (2+ months) with systemic anti-fungal medication.
  • Supportive care such as a nebuliser or oxygen therapy if the cat is experiencing breathing difficulty.
  • Fluid therapy to correct dehydration.
  • If your cat is not eating, then he will need to be encouraged with strong smelling food such as tuna.
  • Your cat may be placed on cage rest or confined to a small room to restrict exercise.

As well as treating pneumonia, addressing the underlying cause will be necessary:

  • Anti-parasitic medications to treat worms and flukes.
  • Supportive care and where necessary anti-virals to treat cat flu.
  • Bronchoscopy to remove a foreign object.
  • Surgery to correct a cleft palate.

Always follow your veterinarian’s instructions and give all medications as prescribed. Your cat will need to have a follow-up appointment and repeat chest x-rays.

What is the prognosis for cats with pneumonia?

Prognosis depends on the underlying cause. The earlier your cat is treated, the better the outcome.

Preventing pneumonia in cats:

  • Keep your cat up to date on his vaccinations.
  • Have your cats desexed, FIV and FeLV are spread via sexual intercourse and bites, nasal secretions (FeLV).
  • Don’t let your cat roam and hunt. Hunting cats are at greater risk of catching parasitic infections.
  • Don’t force liquids or foods into your cat, this exposes them to aspiration pneumonia.
  • Bottle feed kittens with their tummy facing the floor, they should not be held on their backs as we would feed a human baby.