Upper Respiratory Infection in Cats
Most commonly caused by feline herpesvirus-1 or calicivirus, highly prevalent in shelter and multi-cat environments, with herpesvirus capable of causing recurrent flare-ups during stress.
Overview
Feline URI is most often caused by feline herpesvirus-1 (FHV-1) and/or feline calicivirus (FCV). FHV-1 can establish lifelong latency in the body and reactivate during periods of stress, causing recurrent episodes.
Clinical signs
- Sneezing and nasal or ocular discharge
- Conjunctivitis, and with FHV-1 specifically, corneal ulcers
- Oral ulcers, particularly associated with FCV
- Reduced appetite from a diminished sense of smell
- Occasional fever and lethargy
Diagnosis
- Usually a clinical diagnosis based on typical signs
- PCR testing available to identify the specific pathogen(s) in refractory, severe, or shelter-outbreak cases
Treatment
- Supportive care: keeping the eyes and nose clean, and encouraging eating with warmed or aromatic food
- Antiviral medication, such as famciclovir, for severe or recurrent herpesvirus cases
- Antibiotics if a secondary bacterial infection is suspected
Prognosis
Good in most adult cats, with signs typically resolving within one to two weeks. Herpesvirus carriers may have recurrent flare-ups during stress. Kittens and immunocompromised cats are at higher risk of more severe disease.
This page is general reference information for educational purposes. It is not a substitute for an individual clinical assessment, current formulary guidance, or the judgment of a licensed veterinarian treating a specific patient.
Frequently asked questions
Can my cat get upper respiratory infections repeatedly?
Yes - many cats that recover from feline herpesvirus become lifelong carriers and can have recurrent flare-ups, particularly during stressful periods such as boarding, new pets, or household changes.
Is feline URI contagious to other cats?
Yes, it spreads through direct contact and shared items like food bowls and bedding. Cats with active signs should be kept separate from other cats in the household where possible.