Cats

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.

Cats

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

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

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.