Cat flu information sheet

Overview Cat flu or upper respiratory disease associated with several different
infectious agents, which can cause similar signs. Feline herpesvirus
(FHV) or feline calicivirus (FCV) are most commonly involved, other
infections include feline chlamydophilosis and other bacterial
infections, such as Bordetella bronchiseptica (the cause of kennel
cough in dogs), Pasteurella multocida and Mycoplasma species.
Transmission Direct contact with infected or carrier cats’ tears, saliva and nasal/eye
discharge, in some cases indirect contact from the environment.
Bordetella bronchiseptica can be sourced from direct or indirect
contact with infected cats or dogs.
Contagious nature High
Incubation period 2–10 days, depending on the infection involved
Signs of infection Upper respiratory disease, sneezing, nasal/eye discharge,
conjunctivitis, fever, oral ulcers. Symptoms can vary according to the
infection involved, and the pattern of signs may make the vet more
suspicious of specific infectious agents.
Carrier status Varies according to the infection involved, shedding may be for a few
weeks-months or be intermittent – please refer to individual disease
information sheets.
Diagnosis Eye/throat swab, but often managed on clinical signs, without
diagnosis being necessary.
Treatment For viral causes currently no drugs are available to kill these viruses,
so treatment is aimed at supporting the cat through this illness and
treating any signs or secondary infections. For this reason, there is
often no benefit in testing to diagnose which specific infection is
causing the symptoms. For feline chlamydophila infection a 3 week
course of suitable antibiotics and topical treatments such as eye drops
are advised. If this is suspected treatment could be started without a
definitive diagnosis.
Prognosis Generally good, but some cases, such as the very young, very old,
immunosuppressed and unvaccinated cats may be more likely to
develop severe disease and on occasion die as a result of their flu.
Some cats with FHV may develop long term chronic
nasal/eye/airway/sinus disease.
Prevention Primary vaccination course and regular boosters covering FHV and
FCV should be given to all cats. Vaccination does not guarantee
protection, but should in many cases reduce the severity of the
disease. Annual vaccination is also available against feline
chlamydophila, but this is not considered a core vaccination.
Homing Potential owners must be advised that the cat has had cat flu, and that
we don’t know if it is still shedding. They should not be homed with
immunosuppressed or unvaccinated cats due to the increased risk of
them contracting the virus.
Husbandry Isolate and barrier nurse.
Survival in the
Up to 10 days, depending on the infection involved.
Quaternary ammonium, inorganic peroxygen compounds or bleach –
see CP preferred products on CatNav and the Operations section of
the branch/adoption centre manual for further information. Peroxygen
compounds or bleach are generally recommended for environmental
disinfection when managing infectious disease cases in CP cats.
(infectious to
Licensed boarding
cattery stance
Cats should be vaccinated at least 7 days before admission to a
cattery. They may not accept cats showing signs of flu. Isolation
facilities may be available for persistent carriers or cats showing signs
of disease.
Insurance issues May exclude related chronic disease and upper respiratory tract
For more
CP Veterinary Guide: Cat flu
International Cat Care (
Related disease information sheets – Feline Herpesvirus, Feline
Calicivirus and Feline Chlamydophilosis.