Respiratory infections are among the most common illnesses that plague cats. When adopting a cat from an overcrowded shelter or taking in a stray, pay attention to whether they are sneezing or have nasal and eye discharge. These are signs that commonly indicate a respiratory infection, which can spread like wildfire among stray and shelter cat populations. These signs also can recur during times of stress or illness. 

What diseases commonly cause respiratory infections in cats?

Multiple pathogens can lead to respiratory illness, causing similar signs and making it difficult to differentiate among them without diagnostic testing. Some of the most widespread diseases that cause respiratory infections in cats include:

  • Feline viral rhinotracheitis (FVR) — Also known as feline herpesvirus type 1, FVR causes the majority of acute feline upper respiratory infections (URIs). 
  • Feline calicivirus (FCV) — FCV is the second-most common cause of respiratory infections in cats, and also can appear as a dual infection with FVR. Many FCV strains exist that can cause an assortment of illnesses, including salivation, oral ulceration, pneumonia, or joint inflammation. Some strains cause no illness.
  • Chlamydia felis C. felis is primarily a conjunctival pathogen because it always involves the eye. However, it also can cause sneezing and nasal discharge.
  • Mycoplasma felis M. felis often appears in conjunction with other respiratory pathogens, particularly FCV, and can cause infection in the upper and lower respiratory tracts. 

What signs are seen with feline respiratory infections?

Classic signs of a feline respiratory infection include:

  • Sneezing
  • Nasal discharge
  • Conjunctivitis
  • Excessive tearing or eye discharge
  • Salivation
  • Oral ulcerations
  • Fever
  • Rhinitis
  • Lack of appetite
  • Depression

With respiratory infections, transmission occurs easily through aerosol droplets created by sneezing. Items that come in contact with infected cats also can harbor the pathogen and can cause infections when used (e.g., food and water bowls, bedding). The virus can linger in cats for months, and can cause a secondary course of illness during stressful times.

How are feline respiratory infections diagnosed?

Isolating and identifying the cause of a feline respiratory infection can be difficult, especially in FVR infections, because the virus is spread intermittently. Typically, a diagnosis is reached by evaluating clinical signs. For example, FVR tends to affect the conjunctiva and nasal passages, whereas caliciviruses attack the oral mucosa and lower respiratory tract. Chlamydial infections result in chronic, low-grade conjunctivitis. Cytologic examination of conjunctival scrapings aids in the identification of chlamydiae and mycoplasmas. 

How are feline respiratory infections treated?

Treatment for feline respiratory infections—whether viral or bacterial—largely consists of supportive nursing care. Providing adequate nutrition and keeping the infected cat hydrated are key to a positive prognosis. Broad-spectrum antimicrobials are useful in battling secondary bacterial infections, as well as chlamydia and mycoplasma infections. To keep the infected cat comfortable, remove nasal and ocular discharge frequently. A nebulizer or saline nose drops also can be helpful.

Can feline respiratory infections be prevented?
While you cannot completely prevent your cat from developing a respiratory infection, you can minimize their risk.

  • Keep your cat current on vaccinations — Vaccinations for FVR and FCV are available, and while they may not have 100% efficacy in protecting your cat, they can greatly reduce the illness’ severity if they become infected.
  • Quarantine new cats when entering your household — Although it is tempting to welcome every stray you find on your doorstep, enact a quarantine period first. Keep your new cat separate from others in your household for two weeks to monitor for respiratory infection signs and other illnesses or parasites.
  • Practice good hygiene — Good hygiene is essential for thwarting disease transmission. After handling a stray cat, shelter cat, or cat who appears ill, wash your hands thoroughly with soap and water. If you are around a cat who is sneezing, change your clothes and take off your shoes before petting your own cat since pathogens can hitch a ride on your clothes and infect your cat. Do not let sick cats share food and water dishes with healthy cats, and isolate ill cats. Also ensure your ill cat has their own set of resources, like food, water, and bedding.

Protect your cat from a case of the sniffles—and prevent any respiratory infection from turning into a serious illness—by keeping them current on vaccinations. Contact our Emerald Animal Hospital team for an appointment.