Upper Respiratory Infection

Feline upper respiratory infection is a very common viral infection, caused most commonly by calicivirus or herpesvirus. It is compared to the human common cold, and usually lasts for about a week. The viruses are spread through moist contact, like sneezes, infected discharges or sharing dishes.

These viruses are recurring, sometimes over a cat’s entire life. Herpesvirus usually recurs about a week after a stressful incident (like a new pet in the house, boarding, surgery).

Susceptible cats include:

  • Shelter cats
  • Outdoor cats
  • Kittens (because their immune system is not strong) 


The following symptoms indicate a mild infection, just like a human cold:

  • Sneezing and coughing
  • Discharge from the nose, mouth or eyes
  • Ulcers in the nose, mouth or eyes
  • Hoarse voice

If the infection becomes more serious, you will notice the following symptoms:

  • Loss of appetite
  • Difficulty breathing with an open mouth
  • High fever and lethargy

In kittens, these viruses can lead to pneumonia or arthritis. Call your vet immediately.


Your vet may be able to diagnose your cat with a simple physical exam.

Additional tests may include:

  • PCR testing: a simple throat swab which is an extremely sensitive test for viruses in your cat’s DNA
  • Immunofluorescence: uses a fluorescent dye to illuminate viruses or their antibodies in body tissue
  • Radiographs: may show inflammation or infection of the lungs, indicating pneumonia


  • Hospitalization: your cat will be boarded in a cage with proper humidity and oxygen to help breathing
  • IV fluids for dehydration
  • Anti-bacterial medication: This does not help against the actual virus, but will prevent and treat any secondary bacterial infections that can result from the virus
  • Oral medications for ulcers
  • Eye ointments
  • Nose drops for congestion
  • Vaccines


  • Follow the vaccine schedule recommended by your vet
  • Only allow vaccinated cats in your house
  • Separate infected cats from other cats
  • Wash your hands after handling the infected cat, because contaminated hands can spread the disease to other cats
  • Maintain a stress-free environment to prevent recurrence


Your cat may need to be hospitalized to safely survive the symptoms, but there is a very good prognosis. Death in adult cats is unusual; serious illness and death in young kittens is more common.

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