Summary

What is a respiratory tract infection in cats?

A respiratory tract infection occurs when an infectious organism affects part of a cat’s breathing system.

Upper respiratory tract infections mainly affect the nose, nasal passages, sinuses and throat. Eye inflammation and mouth ulcers can accompany these infections.

Lower respiratory tract infections affect the airways within the chest or the lungs. They can cause serious illness, including pneumonia.

“Cat flu” usually refers to the common upper respiratory disease complex. It is not the same as human influenza, and it can involve more than one infectious organism.

Not every sneeze or cough is caused by infection. Irritants, asthma, dental disease and other conditions can cause overlapping signs, so persistent or worsening symptoms need veterinary assessment.

Symptoms of respiratory infections in cats

Common signs of an upper respiratory infection include:

• Sneezing and a blocked or runny nose
• Watery eyes or discharge around the eyes
• Red, inflamed eyes or squinting
• Reduced appetite
• Tiredness, hiding or reduced activity
• Fever
• Drooling or difficulty eating because of mouth ulcers.

Some cats develop painful eye problems, including corneal ulcers. Contact your vet promptly if an eye is held closed, looks cloudy or appears painful.

Coughing, wheezing, rapid breathing or increased effort to breathe need assessment. These signs may indicate lower respiratory disease or another problem rather than an uncomplicated upper respiratory infection.

When to seek urgent veterinary help

Seek emergency veterinary care immediately if your cat:

• Breathes through an open mouth or pants while resting
• Uses obvious effort to breathe, including pronounced movement of the abdomen
• Stretches the neck forward and appears unable to breathe comfortably
• Collapses or becomes severely weak.

Keep your cat calm, minimise handling and call the clinic while arranging transport. Do not delay emergency care to try home treatments.

Contact your vet promptly if your cat stops eating, drinks very little, becomes markedly lethargic or is getting worse. Seek advice early for kittens and cats with existing health problems.

What causes respiratory infections in cats?

Feline herpesvirus

Feline herpesvirus type 1, also called feline viral rhinotracheitis virus, commonly causes sneezing, nasal discharge and eye inflammation. It can also cause corneal ulcers.

After the initial infection, many cats carry the virus in a dormant state. Stress or illness can trigger reactivation, sometimes causing recurrent eye or respiratory signs. A carrier may also shed virus without showing obvious illness.

Feline calicivirus

Feline calicivirus can cause upper respiratory signs and painful mouth ulcers. Some cats develop temporary lameness, and certain infections can cause pneumonia or, rarely, severe disease affecting multiple organs.

Calicivirus should not be described as consistently milder than herpesvirus. Its effects vary, and recovered cats may continue shedding the virus.

Bacterial infections

Bacteria such as Chlamydia felis, Bordetella bronchiseptica and Mycoplasma species can contribute to respiratory or eye disease. Bacterial infections can occur on their own or alongside viral infections.

Identifying the likely cause helps your vet decide whether antibiotics or other treatment are appropriate.

How do cats catch respiratory infections?

Infections can spread through close contact with an infected cat and exposure to saliva, eye discharge or nasal secretions. Contaminated bowls, bedding, carriers, hands and clothing can also transfer infectious material.

Spread is particularly difficult to control in shelters, boarding facilities and other settings where cats live close together. Stress can contribute to illness and reactivate latent herpesvirus infection.

Cats that appear well may still carry or shed an infectious organism. Indoor living reduces some exposures but does not eliminate the risk.

How are respiratory infections diagnosed?

Your vet will ask about symptoms, vaccination history, contact with other cats and previous episodes. The examination may include checking the eyes, mouth, nose, hydration and breathing, and listening to the chest.

An uncomplicated upper respiratory infection can often be assessed without extensive testing. Further investigation may be recommended for severe, persistent or recurrent illness, suspected pneumonia or an outbreak involving several cats.

Tests may include:

• Eye, nasal or throat swabs for selected infectious organisms
• Blood tests to assess general health
• Chest imaging when lower respiratory disease is suspected
• FIV or FeLV testing when relevant to the cat’s history and health.

A positive swab result does not always prove that the detected organism is causing the current illness, because some cats are carriers. Results need to be interpreted alongside the examination and clinical history.

Treatment for respiratory infections in cats

Treatment aims to maintain comfort, hydration and nutrition while addressing any infection or complication that needs specific therapy.

Supportive care and medication

Depending on your cat’s condition, your vet may recommend:

• Fluids to correct dehydration
• Pain relief, particularly for painful mouth or eye disease
• Appropriate eye medication
• Antiviral treatment for selected herpesvirus cases
• Appetite support or assisted nutrition
• Hospitalisation and oxygen for cats with breathing difficulties.

Eye treatments depend on the underlying problem. Do not use leftover eye drops or another pet’s medication without veterinary advice.

Do cats with respiratory infections need antibiotics?

Not always. Antibiotics do not treat viruses and are not routinely needed for an uncomplicated viral infection.

Your vet may prescribe them when a bacterial infection is suspected or identified. Decisions depend on the cat’s overall condition and clinical findings; coloured discharge alone does not automatically establish a need for antibiotics.

Give prescribed medication exactly as directed and contact your vet if administration is difficult or your cat develops adverse effects.

Caring for your cat at home

After veterinary assessment, home nursing may include:

• Keeping your cat comfortable: Provide a quiet resting area with easy access to food, water and a litter tray.
• Cleaning discharge gently: Use a soft cloth or cotton pad moistened with warm water, using separate clean material for each eye.
• Encouraging eating: Offer small, frequent portions of familiar wet cat food. Gently warming it may make its smell more appealing.
• Monitoring closely: Watch appetite, drinking, activity and breathing, and follow the vet’s recheck instructions.

Contact your vet if your cat will not eat or cannot take medication. Feeding support should be planned with the veterinary team.

Do not give human cold medicines, decongestants or painkillers unless your vet has specifically prescribed an appropriate product for your cat. Home care should never delay treatment for breathing difficulty.

How long does recovery take?

Many uncomplicated upper respiratory infections improve over one to two weeks, although signs can last around three weeks or longer in some cases. Severe infections and complications can take substantially longer.

Arrange reassessment if your cat is deteriorating, is not improving as expected or has persistent discharge, coughing or eye problems.

Recovery from the initial illness does not always mean the infectious organism has been eliminated. Some cats experience recurrent herpesvirus flare-ups or develop ongoing nasal or eye problems.

Preventing respiratory infections in cats

Keep vaccinations up to date

Australia’s core F3 vaccination protects against feline herpesvirus, feline calicivirus and feline panleukopenia.

Herpesvirus and calicivirus vaccines help reduce disease severity, but vaccinated cats can still become infected or shed virus. Your vet will recommend a vaccination schedule based on age, previous vaccinations and exposure risk.

See our cat and kitten vaccination guide.

Reduce exposure and stress

Keep an affected cat separate from other cats, with dedicated bowls, bedding and litter equipment. Wash your hands between handling cats and clean contaminated items.

Ask your vet which disinfectant is appropriate. Calicivirus is more resistant to some cleaning products than herpesvirus, so ordinary cleaning alone may not be sufficient.

Follow veterinary advice about when cats can mix again rather than assuming that the disappearance of symptoms means transmission is no longer possible. Maintain predictable routines and provide hiding places and separate resources to help reduce stress.

What does treatment cost?

Costs depend on the severity of illness and the tests and treatment required. An uncomplicated infection may need an examination and supportive care, while dehydration, painful eye disease or pneumonia can require additional medication, imaging or hospitalisation.

Ask your vet for an estimate that explains the recommended treatment and likely follow-up costs. Broad respiratory-disease claims averages should not be treated as a price estimate for an individual cat’s upper respiratory infection.

Because it is difficult to predict the costs of veterinary care, it can help to have measures in place to help prepare for the unexpected. Pet insurance can help by covering a portion of the eligible vet bill if the unexpected does happen.

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In a nutshell

Respiratory infections in cats commonly cause sneezing, nasal congestion and eye discharge, but their severity varies. Many cats recover well with appropriate care, while kittens and cats with other health problems may need more intensive treatment.

Seek veterinary advice if your cat stops eating, develops painful eyes or is getting worse. Open-mouth breathing or difficulty breathing requires immediate veterinary attention.

Vaccination, good hygiene and reduced stress help protect your cat. Because some cats remain carriers after recovering, follow your vet’s advice about contact with other cats.

Sources

“Respiratory Infections”, Cornell University College of Veterinary Medicine, Cornell Feline Health Center. https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/respiratory-infections. Accessed 29 October 2026.

“Dyspnea (Difficulty Breathing)”, Cornell University College of Veterinary Medicine, Cornell Feline Health Center. https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/dyspnea-difficulty-breathing. Accessed 29 October 2026.

“Feline Respiratory Disease Complex”, Merck Veterinary Manual, updated November 2024. https://www.merckvetmanual.com/respiratory-system/respiratory-diseases-of-small-animals/feline-respiratory-disease-complex. Accessed 29 October 2026.

“Feline Upper Respiratory Infection”, VCA Animal Hospitals. https://vcahospitals.com/know-your-pet/feline-upper-respiratory-infection. Accessed 29 October 2026.

“Guideline for Feline Herpesvirus infection”, European Advisory Board on Cat Diseases (ABCD), updated 14 May 2026. https://www.abcdcatsvets.org/guideline-for-feline-herpesvirus-infection/. Accessed 29 October 2026.

“Guideline for Feline calicivirus infection”, European Advisory Board on Cat Diseases (ABCD), updated 27 March 2025. https://www.abcdcatsvets.org/guideline-for-feline-calicivirus-infection/. Accessed 29 October 2026.

“Antimicrobial use Guidelines for Treatment of Respiratory Tract Disease in Dogs and Cats”, Lappin et al., Journal of Veterinary Internal Medicine / International Society for Companion Animal Infectious Diseases (ISCAID), 2017. https://www.amrvetcollective.com/assets/guidelines/ISCAID_Respiratory_-2017.pdf. Accessed 29 October 2026.

“Feline Upper Respiratory Infection”, ASPCApro. https://www.aspcapro.org/topics-shelter-medicine-common-diseases/feline-upper-respiratory-infection. Accessed 29 October 2026.

“Feline Upper Respiratory Infection (URI)”, Schwarzman Animal Medical Center, updated 18 October 2024. https://www.amcny.org/pet_health_library/feline-upper-respiratory-infection-uri/. Accessed 29 October 2026.

“What vaccinations should my cat receive?”, RSPCA Australia, updated 30 April 2025. https://kb.rspca.org.au/categories/companion-animals/cats/caring-for-my-cat/what-vaccinations-should-my-cat-receive. Accessed 29 October 2026.

“Nose-to-Tail Cover”, Bow Wow Meow Pet Insurance. https://bowwowinsurance.com.au/cover-options/. Accessed 29 October 2026.

“Nose-to-Tail Cover Product Disclosure Statement”, Bow Wow Meow Pet Insurance, 6 November 2024. https://bowwowinsurance.com.au/wp-content/uploads/2024/11/Bow-Wow-Meow_Nose-to-Tail-Cover-PDS_03A_bwm11_06112024.pdf. Accessed 29 October 2026.