A feline upper respiratory infection (URI) is essentially a cat cold — an infection of the nose, throat, and sinuses that causes sneezing, congestion, and eye discharge. Most cases are caused by one of two viruses, and while mild infections typically clear up within one to two weeks, some cats become lifelong carriers with recurring flare-ups. Here's what pet parents need to know.
What Is an Upper Respiratory Infection in Cats?
A feline URI is an infection affecting the upper airways — nose, sinuses, throat, and eyes. According to VCA Animal Hospitals¹, feline herpesvirus type-1 (FHV-1) and feline calicivirus (FCV) together account for roughly 90% of all feline URIs. Bacterial agents — including Bordetella bronchiseptica and Chlamydophila felis — make up most of the remaining cases and can also complicate viral infections.
Cat-to-cat transmission is efficient. The virus spreads through direct nose-to-nose contact, shared food and water bowls, and contact with contaminated surfaces. This makes multi-cat households, shelters, and boarding facilities higher-risk environments.
What Are the Signs of a Cat Upper Respiratory Infection?
Symptoms vary by cause and severity, but common signs include:
Sneezing — often frequent and forceful, sometimes producing discharge
Nasal discharge — clear at first, may become thick or yellow-green with secondary bacterial infection
Eye discharge — from mild watering to thick crusting around the eyes
Congestion — audible stuffiness, open-mouth breathing in severe cases
Reduced appetite — cats rely on smell to find food appealing; congestion suppresses it
Lethargy — less energy, less interest in activity
Mouth ulcers or drooling — associated specifically with calicivirus infection
Fever and enlarged lymph nodes can occur in more severe cases.¹ Some infections look deceptively mild at first but worsen over a few days, so monitoring is important.
What Causes Upper Respiratory Infections in Cats?
Feline herpesvirus-1 (FHV-1) is the most common cause of feline URI. PetMD² notes that an estimated 97% of cats will be exposed to FHV-1 at some point in their lives. The virus causes typical cold symptoms plus eye inflammation, and it can affect the cornea in severe cases.
A critical feature of FHV-1 is its carrier state. According to VCA Animal Hospitals¹, approximately 80% of cats who recover from FHV-1 infection become lifelong carriers. These cats can experience flare-ups — sneezing, eye discharge, and congestion — when stressed or immunocompromised, even years after the initial infection.
Feline calicivirus (FCV) causes a similar respiratory illness but is also known for causing painful oral ulcers and drooling. About half of recovered cats carry FCV and can intermittently shed the virus.¹ Multiple strains circulate, so even vaccinated cats can become infected — though vaccination significantly reduces severity.
Bacterial agents — especially Bordetella bronchiseptica and Chlamydophila felis — typically act as secondary infections on top of viral disease, prolonging recovery and requiring antibiotic treatment.²
How Long Does a Cat URI Last?
Most uncomplicated feline URIs resolve within 7 to 14 days, though some cases persist up to 21 days.¹ The incubation period — time from exposure to visible symptoms — is typically 2 to 10 days. Kittens, immunocompromised cats, and senior cats often take longer to recover and are more likely to develop complications.
Cat Upper Respiratory Infection Treatment
Mild URIs often resolve with supportive care at home:
Encourage eating — warming wet food enhances aroma and makes it more appealing to a congested cat
Steam and humidification — sitting with your cat in a steamy bathroom for 10–15 minutes helps loosen nasal congestion
Keep eyes and nose clean — gently wipe discharge with a warm, damp cloth to keep passages clear
Ensure hydration — dehydration is a real risk when cats stop eating and drinking
When veterinary treatment is needed, options include:²
Antibiotics — to address secondary bacterial infections (antibiotics don't treat viruses, but they prevent complications)
Antiviral medication — famciclovir is used for severe or recurrent FHV-1 infections
Eye medications — topical antivirals or antibiotics for eye discharge and corneal involvement
Appetite stimulants — for cats that stop eating and are at risk of hepatic lipidosis
Fluid therapy — for dehydrated or hospitalized cats with severe illness
For a sense of what a veterinary visit and workup typically costs, see how much does a vet checkup cost.
When Should You See a Vet?
Take your cat in promptly if you notice:
No eating for 24–48 hours — cats that stop eating can develop fatty liver disease quickly
Labored or open-mouth breathing — a sign of significant respiratory involvement
Symptoms worsening after day 4–5 — rather than improving
Kittens or senior cats — they are more vulnerable to rapid deterioration
Symptoms beyond two weeks — may indicate bacterial complication or a secondary condition
Even in mild-seeming cases, a vet can confirm the diagnosis, rule out more serious conditions, and start treatment before complications develop.
How to Prevent Respiratory Illnesses in Cats
Vaccination is the most important preventive step. The FVRCP vaccine protects against FHV-1 and FCV — the two viruses responsible for the majority of feline URIs. Vaccination doesn't guarantee a cat will never be infected, but it significantly reduces the severity and duration of illness. Learn more in the importance of vaccinating your dog or cat.
Isolation for new cats — newly adopted cats or cats returning from boarding should be kept separate from resident cats for two to three weeks, since a cat can be incubating or shedding a URI without obvious symptoms.
Hygiene in multi-cat households — separate food and water bowls, regular cleaning of shared surfaces, and prompt separation of symptomatic cats all help limit spread.
Frequently Asked Questions
Is a cat upper respiratory infection contagious to humans?
No — the viruses that cause most feline URIs (FHV-1 and FCV) are species-specific and cannot infect humans. However, Bordetella bronchiseptica can occasionally affect people with compromised immune systems, so basic hygiene after handling a sick cat is still recommended. The risk to healthy adults is extremely low.
Can cats recover from a URI without veterinary treatment?
Mild cases often resolve with supportive care — keeping the cat warm, encouraging eating, wiping discharge, and using humidification. However, cats who stop eating, are very young or old, or show worsening symptoms need veterinary attention. Without a vet visit, it's also not possible to determine whether a bacterial infection is complicating recovery and needs antibiotics.
Can a cat carry URI without showing symptoms?
Yes. A large percentage of cats who recover from FHV-1 infection become lifelong carriers without persistent symptoms. These cats can shed the virus — especially during stressful periods — and infect other cats without appearing sick themselves. This is why isolation protocols for new cats matter even when the newcomer looks healthy.
Does pet insurance cover upper respiratory infections in cats?
Accident and illness pet insurance plans typically help cover URI diagnosis and treatment as long as the condition isn't pre-existing at enrollment. Coverage can include exam fees, diagnostics, medications, and follow-up care. Routine vaccines that prevent URIs are generally covered only through an optional preventive care add-on. See is cat insurance worth it for more on evaluating coverage for your cat.
The right pet insurance plan should help support your pet through both unexpected accidents and health needs. Understanding what's included in your policy can help you choose coverage that fits your pet's lifestyle.
Spot Pet Insurance offers accident and illness coverage to help reimburse eligible costs related to covered injuries, illnesses, diagnostics, and treatment. Pet parents can also add optional preventive care coverage for routine services like annual exams, dental cleanings, and certain vaccines. Learn more about what pet insurance covers.
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VCA Animal Hospitals. "Feline Upper Respiratory Infection." VCA Animal Hospitals. https://vcahospitals.com/know-your-pet/feline-upper-respiratory-infection
PetMD. "Upper Respiratory Infection in Cats." PetMD. https://www.petmd.com/cat/conditions/respiratory/upper-respiratory-infection-cats
