Respiratory infections are one of the most common infectious diseases seen in cats. The infections range widely in severity, can lead to lifelong illness that reappears when cats are stressed, and may result in life-threatening illness. 

Although viruses cause the majority of feline respiratory infections, symptomatic treatment can prevent your cat’s condition from worsening and speed their recovery. Learn how to spot a respiratory infection in your cat, so you can get them immediate care.

What causes feline respiratory infections?

Two viruses, feline calicivirus (FCV) and feline herpesvirus type 1 (FHV-1), are believed to cause roughly 90% of all feline respiratory infections.

  • Feline calicivirus — FCV generally causes more severe oral problems than ocular, and results in painful oral ulcers and drooling. FCV is also thought to cause chronic gingivitis and stomatitis in cats. FCV-infected cats shed the virus continually, not only during stressful times, and may do so for life.
  • Feline herpesvirus type 1 — FHV-1 largely causes ocular problems and tends to result in more severe illness than FCV. FHV-1-infected cats often exhibit marked conjunctivitis, ocular discharge, and corneal ulcers, and may also develop tracheal inflammation and coughing. Stress episodes (e.g., from boarding, household changes, new pets) can induce FHV-1 signs to flare up, potentially throughout your cat’s life.

Other important feline respiratory infection causes include:

  • Bordetella bronchiseptica — This bacterial agent commonly causes disease in crowded housing situations, and can lead to sneezing, nasal discharge, and occasional coughing.
  • Chlamydophila felis — This bacterial infection mostly causes conjunctivitis, but can lead to other respiratory illness signs, such as severe ocular and nasal discharge. 

What are feline respiratory infection signs?

Respiratory infections cause similar clinical signs in cats, regardless of the inciting pathogen. If your cat develops a respiratory infection, you may notice:

  • Sneezing
  • Nasal discharge
  • Ocular inflammation (i.e., conjunctivitis)
  • Ocular discharge
  • Corneal ulcers
  • Appetite loss
  • Fever
  • Lethargy
  • Oral ulcers
  • Bad breath
  • Excessive drooling
  • Coughing
  • Breathing difficulties

Cats with respiratory infections can rapidly become dehydrated and weak, because their nutrition is inadequate. Nasal discharge in affected cats hinders their sense of smell and their food is no longer appealing, while oral ulcers can be too painful for cats to comfortably eat and drink.

How are feline respiratory infections transmitted?

Respiratory infections are highly contagious and can spread easily through direct and indirect contact. Susceptible cats can become ill by grooming if they are in sneezing distance of a sick cat, or from exposure to infectious particles on bowls, bedding, and litter boxes.

Most cases are transmitted through direct contact, because the responsible pathogens do not survive long in the environment and can readily be killed by disinfectants.

Cats can also be respiratory disease carriers and transmit infection, despite appearing healthy.

How are feline respiratory infections diagnosed?

A respiratory infection diagnosis is often based on characteristic clinical signs, including sneezing, nose and eye discharge, and oral ulcers. Identifying the causative agent typically isn’t necessary, unless an infected cat fails to respond to treatment.

How are feline respiratory infections treated?

Since viruses cause the majority of feline respiratory infections, treatment focuses on supportive nursing care until the immune system can fight off the virus. However, despite the infection being viral, affected cats, particularly kittens, are often given antibiotics to prevent secondary infections.

Treatment may also include oral and nasal drops to help battle discharge, steam inhalation or nebulization to ease congestion, and a feeding tube placed to bypass oral ulcers. Keeping your cat’s eyes and nose clean is also important for their overall wellbeing and to promote recovery.

How can I prevent my cat from getting a respiratory infection?

Regularly vaccinating your cat against FCV and FHV-1 is the best way to prevent them from contracting respiratory infections. Bordetella vaccinations are also available for cats, but are rarely administered, except when breeding. Keep in mind—vaccination is highly effective at preventing illness, but cannot fully protect against every calicivirus strain. Despite this, the calicivirus vaccine will still reduce infection severity if your cat contracts this virus, so we recommend routine vaccination for all cats.

In addition to regular vaccination, good hygiene is critical for preventing respiratory infection spread. Bleach is particularly effective against viral agents, so if your cat is infected, use a bleach solution to disinfect bowls, bedding, and litter boxes to help prevent transmission.

Respiratory infections may not cause severe illness, but they can lead to a lifetime of infection and flares of clinical signs. Protect your feline friend from respiratory infections by staying up to date on their vaccinations with regular wellness care from your Aberdeen Veterinary Clinic team. Give us a call to schedule an appointment.