Upper respiratory infections are mainly caused by viral infections, however, in rare cases bacterial infections may be responsible.
Feline Herpesvirus (FHV)
A more severe form of virus that remains in the cat’s body for the rest of its life. Eye infections are commonly seen with this virus, along with coughing, sneezing, loss of appetite, pharyngitis (sore throat) and inflamed trachea. The virus will manifest itself whenever the cat experiences a time of stress thereafter in its life, with the cat being potentially contagious forever.
Feline Calicivirus (FCV)
Less severe symptoms are experienced with this virus although more mouth ulceration may be present. There is also an increased risk of developing pneumonia with this virus. The cat may become a carrier once recovered, and could then be contagious whenever shedding the virus.
Bordetella Bronchiseptica
A bacterial infection that may cause upper respiratory problems in cats. Generally associated with fever, sneezing, swollen lymph nodes and lung complications.
Chlamydophila Felis
A bacterial infection often associated with eye infections and mild sneezing.
Mycoplasma
A bacterial infection with symptoms of ocular discharge and eye swelling.
Feline Reovirus
A viral infection of the intestines that can sometimes mimic symptoms of a respiratory infection.
Pasteurella
A bacterial infection that is often transmitted via animal bites.
All of the aforementioned infections become rampant in situations where many cats are in contact with each other. Because of this, animal shelters, feral cat colonies, and any other large group of cats are at the highest risk of housing viral or bacterial infection epidemics. These upper respiratory infections can be spread from cats hissing, spitting, grooming or even sleeping near each other. Sharing food dishes or litter boxes can also spread infection.