Understanding Feline Upper Respiratory Infections: Causes, Symptoms, Treatment, and Prevention

Early recognition and supportive care help cats recover faster with fewer complications.

By Anjali Sayee

Created on Aug 29, 2025

Early recognition and supportive care help cats recover faster with fewer complications.

Cats are susceptible to a variety of infectious diseases, with upper respiratory infections (URIs) ranking among the most frequent ailments affecting domestic felines. These infections, often likened to the ‘common cold,’ can vary from mild and self-limiting to severe, particularly in kittens, older cats, or those with compromised immune systems. This guide delivers an in-depth overview of the causes, symptoms, diagnostic methods, treatment strategies, and preventive measures for feline upper respiratory infections, helping cat owners and caregivers safeguard the well-being of their pets.

What is a Feline Upper Respiratory Infection?

Feline upper respiratory infection (URI) refers to a group of contagious diseases that target a catâs nasal passages, sinuses, pharynx, and sometimes the eyes. Known alternatively as feline infectious respiratory disease or the feline upper respiratory disease complex (URD), URIs commonly involve a mix of viral and bacterial pathogens. While typically not life-threatening for healthy adults, URIs can lead to significant discomfort, secondary complications, and, in some cases, persistent carrier states.

Causes of Upper Respiratory Infection in Cats

URIs are most frequently caused by a combination of viruses and bacteria. The interplay of these agents determines both the severity and course of each infection. The most prevalent microorganisms are:

Feline Herpesvirus type-1 (FHV-1) / Feline Viral Rhinotracheitis (FVR): Responsible for about half of feline URIs, FHV-1 leads to recurring infections and can cause lifelong latent viral carriage.
Feline Calicivirus (FCV): Alongside FHV-1, FCV accounts for approximately 80-90% of upper respiratory infections. Some strains can cause oral ulcers in addition to respiratory symptoms.
Bordetella bronchiseptica: This bacterium is associated with kennel cough in dogs but can infect cats, particularly in densely populated settings.
Chlamydophila felis: Primarily causes conjunctivitis but can contribute to respiratory symptoms.
Mycoplasma species, Influenza A, and Feline reovirus: These are less common but can be involved, especially in mixed infections.

Several factors may increase a catâs risk of developing a URI, including:

Living in crowded or stressful environments (such as shelters or catteries)
Poor ventilation
Lack of vaccination
Immunosuppression from chronic disease or certain medications
Age (kittens and seniors are more vulnerable)

How Cats Get Upper Respiratory Infections

The pathogens responsible for URIs are highly contagious, especially in multi-cat environments. The primary means of transmission include:

Aerosolization: Virus-laden droplets expelled through sneezing or coughing can infect nearby cats.
Direct Contact: Mutual grooming, nose-to-nose interactions, or shared food/water bowls facilitate spread.
Fomites: Contaminated bedding, food dishes, or human hands can serve as indirect vehicles for transmission.

Importantly, some infected cats become carriers without showing symptoms and can intermittently shed pathogens, particularly under stress, posing an ongoing risk to others in their environment.

Symptoms of Feline Upper Respiratory Infection

Symptoms typically appear 2â10 days after exposure, with the severity influenced by the specific pathogens and the catâs health status. Common signs include:

Sneezing
Nasal congestion and discharge (can range from clear to thick, yellow, or green)
Coughing
Conjunctivitis (red, swollen eyes)
Eye discharge (watery, cloudy, or pus-like)
Oral ulcers (especially with calicivirus; may result in drooling or oral pain)
Fever
Enlarged lymph nodes
Lethargy
Loss of appetite
Squinting or blepharospasm

Severe and Emergency Symptoms

While many cases are mild, the following symptoms warrant immediate veterinary attention:

Open-mouth breathing or pronounced difficulty breathing
Persistent refusal to eat or drink (>24 hours)
Severe lethargy or collapse
Blue or pale gums
Heavy, thick eye or nasal discharge with swelling

Delaying medical attention in these cases can quickly result in life-threatening complications, such as pneumonia or systemic infection.

Diagnosing Upper Respiratory Infections in Cats

Diagnosis is primarily based on clinical signs and the catâs exposure history. In most mild, uncomplicated cases, laboratory confirmation is unnecessary. However, testing can be crucial when:

The illness is unusually severe or prolonged
Multiple cats are affected (especially in shelters)
The response to treatment is poor

Veterinarians may use PCR (polymerase chain reaction) panels to test for the presence of viral and bacterial pathogens, ensuring more precise treatmentâespecially when coinfections are involved. Additional tests, such as chest X-rays, may be recommended if pneumonia or other complications are suspected.

Treatment of Feline Upper Respiratory Infection

Treatment focuses on alleviating symptoms, preventing secondary infections, and supporting the catâs immune system. The main components include:

Isolation: Infected cats should be separated from healthy animals to prevent disease spread.
Supportive care:
- Provide a quiet, comfortable, and warm resting area.
- Keep food and water accessible.
- Monitor and support hydration. Subcutaneous fluids or IV therapy may be needed in severe cases.
- Gently clean nasal and eye discharge with a soft, damp cloth.
Dietary support: Since cats rely on their sense of smell to eat, offer highly palatable, aromatic foods (such as warmed canned foods, fish, or kitten formula foods). Tempt cats that are reluctant to eat and consult a veterinarian if anorexia lasts more than 24 hours.
Medical therapy:
- Antibiotics are prescribed if there is evidence of secondary bacterial infection (they are not effective against viruses).
- Antiviral medications may be used in severe or chronic herpesvirus infections.
- Eye drops or ointments are indicated if there is conjunctivitis or ocular ulceration.
- Non-steroidal anti-inflammatory drugs (NSAIDs) or other pain relief options may be provided, especially when oral ulcers or eye pain is present.
Humidification: Steam inhalation or using a vaporizer can help loosen nasal congestion and ease breathing. Placing the cat in a steamy bathroom for 10-15 minutes can be beneficial.

More intensive care, including hospitalization, feeding tubes, or oxygen therapy, may be necessary for severely affected or at-risk cats who refuse food/water or develop breathing difficulties.

Recovery, Prognosis, and Complications

With prompt and appropriate care, most cats recover from an uncomplicated URI within 7 to 14 days. However, several lingering effects are possible:

Chronic nasal discharge or sneezing: Some cats may have persistent symptoms even after the initial infection clears.
Recurrent flare-ups: Especially with feline herpesvirus, cats can experience periodic relapses, particularly during times of stress or immunosuppression.
Carrier state: Many cats remain lifelong carriers of FHV-1 or calicivirus, intermittently shedding virus and posing a risk to other cats without appearing ill themselves.
Complications: These can include pneumonia, eye ulcers (which may threaten vision if untreated), and chronic breathing problems.

Return to normal activity levels and appetite are good indicators of recovery. If a cat does not respond to supportive care, experiences relapses, or develops new symptoms (such as difficulty breathing, severe lethargy, or swelling), further veterinary intervention is required.

Prevention of Feline Upper Respiratory Infection

While not all URIs can be prevented, certain steps can significantly reduce the risk and severity of infections:

Vaccination: Routine vaccines (FVRCP) cover FHV-1, calicivirus, and panleukopenia. While vaccines may not prevent infection entirely, they reduce severity and duration.
Minimize Exposure: Keep cats indoors or restrict their contact with unknown cats, especially in outbreak areas or shelters.
Proper Hygiene: Disinfect bedding, bowls, litter boxes, and toys. Wash hands thoroughly after handling sick or multiple cats.
Reduce Stress: Stress can cause latent carriers to shed virus. Provide hiding places, regular routines, and enrichment to lower stress in multi-cat households.
Prompt Isolation: Separate infected or newly introduced cats from resident cats until cleared by a veterinarian.
Regular Health Checks: Routine vet visits and early intervention can help catch and treat problems before they worsen.

Table: Common Pathogens Responsible for Feline URIs

Pathogen	Type	Main Symptoms	Notes
Feline Herpesvirus (FHV-1 / FVR)	Virus	Sneezing, conjunctivitis, ocular/nasal discharge	Lifelong carrier state possible, relapses
Feline Calicivirus (FCV)	Virus	Oral ulcers, nasal/eye discharge, sometimes joint pain	Multiple strains, some cause severe disease
Bordetella bronchiseptica	Bacterium	Coughing, nasal discharge	Common in crowded or shelter environments
Chlamydophila felis	Bacterium	Conjunctivitis, mild respiratory signs	Eye involvement is prominent
Mycoplasma spp.	Bacterium	Variable respiratory symptoms	Usually part of mixed infection

Living with and Caring for Cats Who Have Had URIs

Cats that recover from a URI can generally resume normal lives, but awareness of the potential for virus shedding and relapses is important. For multi-cat homes or breeders:

Maintain strict hygiene and limit introductions of new cats without proper quarantine.
Monitor all cats for early signs of illness and intervene promptly.
Understand that latent carrier cats, especially those infected with FHV-1, may shed viruses when stressed or ill.
Consult with your veterinarian about long-term management or vaccination strategies if frequent relapses occur.

Frequently Asked Questions (FAQs) About Feline Upper Respiratory Infections

Q: Can humans catch upper respiratory infections from their cats?

A: The viruses and bacteria causing most feline upper respiratory infections are species-specific and do not pose a risk to humans. However, good hygiene is always recommended to prevent the spread of less common zoonotic agents.

Q: How long does a typical feline URI last?

A: Most cats recover from an uncomplicated URI within 1â2 weeks. Persistent, severe, or recurring symptoms require veterinary evaluation.

Q: Should I keep my sick cat away from my other pets?

A: Yes. Infected cats can easily transmit URI pathogens to other cats, particularly in the early stages of illness. Isolation is important until a veterinarian confirms the cat is no longer contagious.

Q: Is vaccination enough to protect my cat?

A: Vaccination greatly reduces the severity and likelihood of severe illness, but it does not provide absolute immunity. Vaccinated cats can still contract and transmit infection, though usually in milder forms.

Q: When should I see a veterinarian for a cat with URI symptoms?

A: Seek prompt veterinary care if your cat:

Breathes through the mouth
Refuses food or water for more than 24 hours
Shows severe lethargy, dehydration, or persistent fever
Develops swelling around the eyes or thick green/yellow discharge

Summary

Feline upper respiratory infections are common, multi-causal illnesses affecting cats of all ages. Early recognition of symptoms, proactive treatment, supportive care, adherence to vaccination protocols, and preventive hygiene measures are key to reducing impact and spread. By understanding the complexities and adopting best practices, cat owners can promote faster recovery and help prevent future outbreaks in their feline companions.

References

Author

Anjali Sayee

Anjali is an Associate Editor at StyleCraze with 7 years of experience specializing in hairstyles, hair care, and skin care. She has authored over 300 articles and offers expert advice on hair styling techniques, effective skin care routines, and tips for maintaining healthy hair and skin.

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