Upper Respiratory Infection in Cats

Feline upper respiratory infections are common and often contagious, especially in kittens and multi-cat settings. Because cats can hide illness well, early signs like sneezing, eye discharge, or reduced appetite should be taken seriously.

Talk to a vet

Urgent

Contact your vet promptly if your cat has breathing trouble, won’t eat, or seems unusually quiet.

Many upper respiratory infections are mild and self-limiting, but cats can worsen quickly if congestion prevents eating or drinking. Seek urgent veterinary care right away for open-mouth breathing, labored breathing, severe lethargy, dehydration, or symptoms in very young kittens, senior cats, or immunocompromised cats.

Symptoms to Watch For

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Sneezing

Frequent sneezing is one of the most common early signs.

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Eye discharge

Watery, mucus-like, or pus-like discharge may affect one or both eyes.

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Nasal discharge or congestion

A stuffy or runny nose can make it hard for cats to smell food.

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Reduced appetite

Cats may eat less when they cannot smell well or feel unwell.

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Lethargy

Some cats become quieter, sleep more, or hide more than usual.

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Coughing or noisy breathing

These signs can occur with more severe irritation or when lower airways are involved.

What Causes Upper Respiratory Infection

Feline upper respiratory infection is usually caused by contagious viral infections, most commonly feline herpesvirus-1 and feline calicivirus. Bacteria such as Chlamydophila felis, Bordetella bronchiseptica, and Mycoplasma species may act as primary causes in some cases or contribute as secondary infections. Stress, crowding, poor ventilation, and close contact with infected cats increase spread, especially in shelters, catteries, and multi-cat homes. Young kittens and older cats are more vulnerable, and brachycephalic cats may be more prone to chronic breathing-related problems after infection. Cats that recover can sometimes remain carriers, especially with herpesvirus, and may have flare-ups later during stress.

Most common infectious causes: feline herpesvirus-1 and feline calicivirus
Bacterial contributors can include Chlamydophila felis, Bordetella bronchiseptica, and Mycoplasma species
Higher risk in kittens, senior cats, unvaccinated cats, and cats in shelters or crowded housing
Stress and concurrent illness can increase severity or trigger recurrence
Brachycephalic breeds may have a higher risk of chronic upper airway issues

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How It's Diagnosed

Veterinarians often diagnose an upper respiratory infection based on your cat’s symptoms, history, vaccination status, and physical exam. They may check the eyes, nose, mouth, temperature, hydration status, and breathing effort. In uncomplicated cases, advanced testing is not always needed. If signs are severe, prolonged, recurrent, or unusual, your vet may recommend PCR testing or swabs to look for specific infectious agents, bloodwork, imaging such as skull or chest radiographs, or sedation-based exams to assess the nasal passages and throat. Cats with long-lasting congestion or discharge may also need evaluation for chronic rhinitis, dental disease, polyps, tumors, or fungal disease.

Physical exam and history are often enough for initial diagnosis
PCR or other infectious disease testing may be used in persistent or outbreak cases
Bloodwork and imaging may help rule out complications or other causes
Expect your vet to assess hydration, appetite, fever, and breathing effort

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Treatment Options

Treatment depends on the cause and severity. Mild cases are often managed with supportive care such as keeping the nose and eyes clean, encouraging food and water intake, reducing stress, and using humidity or steam from a bathroom to help loosen secretions. Your veterinarian may prescribe medications for secondary bacterial infection, eye disease, pain from oral ulcers, or other complications. Some cats need appetite support, fluids, or hospitalization if they become dehydrated or stop eating. Antibiotics are not needed for every case, since many infections are viral, so treatment should be guided by a veterinarian. Call your vet promptly if your cat is not eating, seems dehydrated, or has trouble breathing.

Supportive care is the mainstay for many mild viral infections
Veterinary-prescribed treatment may include eye medications, fluids, or other supportive therapies
Antibiotics may be used when bacterial infection is suspected or confirmed
Hospital care may be needed for dehydration, poor appetite, or breathing difficulty
Vaccination and stress reduction help lower future risk, though vaccines do not prevent every infection

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Main viral causes

Up to 3 weeks

Contagious period

Young or very old cats

Typical age risk

$100–$800+

Typical cost

Living with Upper Respiratory Infection

Before

After

Waiting for obvious illness

Monitor for subtle signs like hiding, reduced appetite, squinting, or mild congestion, since cats often mask discomfort.

Offering food as usual

Try warming food or offering strong-smelling wet food if congestion is making meals less appealing.

Letting discharge build up

Gently clean nasal and eye discharge with a soft damp cloth if your cat tolerates it.

Assuming all sneezing is minor

Call your vet if symptoms last more than a few days, recur often, or are paired with poor appetite, fever, or breathing changes.

Frequently Asked Questions

Can a cat upper respiratory infection go away on its own?

Some mild cases improve with supportive care, especially when caused by viruses, but not every cat should be managed at home. Cats that stop eating, seem dehydrated, have eye pain, develop breathing difficulty, or fail to improve should see a veterinarian promptly.

How do cats catch upper respiratory infections?

Cats usually catch these infections from other cats through respiratory droplets, direct contact, shared bowls, bedding, grooming, or contaminated hands and objects. Risk is higher in shelters, catteries, rescue settings, and multi-cat homes.

Is an upper respiratory infection in cats contagious to other cats?

Yes. Many feline upper respiratory infections are highly contagious to other cats, especially herpesvirus and calicivirus. Isolate sick cats when possible, wash hands between handling cats, and disinfect shared items.

When should I take my cat to the vet for sneezing and congestion?

Call your vet if symptoms are significant, last more than a few days, keep returning, or are accompanied by poor appetite, eye discharge, lethargy, fever, dehydration, or any change in breathing. Kittens, senior cats, and cats with chronic disease should be seen sooner.

Can vaccinated cats still get upper respiratory infections?

Yes. Vaccination helps reduce the severity and spread of common infections, but it does not prevent every case. Vaccinated cats can still become infected, especially after exposure to virulent strains or if boosters are overdue.

Are some cat breeds more prone to problems?

Flat-faced, brachycephalic cats may be more likely to have ongoing airway-related issues or chronic signs after infection because of their skull and airway shape. Breed is only one factor, and any cat can develop an upper respiratory infection.

Sources

Disclaimer: The information provided in this article is for educational purposes only and does not constitute veterinary medical advice. Reading this content does not establish a veterinarian-client-patient relationship. Every pet is different — always consult a licensed veterinarian before making decisions about your pet's health, diet, or care. If you'd like personalized guidance, you can talk to one of our vets. If your pet is experiencing a medical emergency, contact your local emergency animal hospital immediately.

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