Upper Respiratory Infection in Cats: Cat Colds, Signs and Care

What causes upper respiratory infections in cats

VCA Animal Hospitals reports that feline herpesvirus type 1 and feline calicivirus cause about 90 percent of feline upper respiratory infections. Bacteria such as Bordetella bronchiseptica and Chlamydophila felis cause some of the rest, and bacteria often move in as a second infection once a virus has damaged the lining of the nose and eyes.

These infections spread easily through saliva and eye and nose discharge, either by direct contact or on shared bowls, litter boxes, toys, bedding and hands. Cornell's Baker Institute notes that calicivirus can survive on surfaces for up to a month. That is why they are so common in shelters, catteries and boarding facilities. Most cats infected with herpesvirus carry it for life, and stress such as boarding, surgery or a move can bring on a fresh flare-up months or years later.

Signs of a cat cold

Signs usually appear between two days and two weeks after exposure. The classic picture is sneezing, a congested or runny nose and inflamed, watery eyes, with discharge that may turn thick and yellow or green. Many cats also have a fever, lose interest in food, seem tired and may have swollen glands under the jaw. Squinting is common when the eyes are sore.

Calicivirus often causes painful ulcers on the tongue and in the mouth, which make cats drool and avoid eating, and Cornell notes it can also cause a brief lameness. A poor appetite is one of the most common signs, and it is the one that most often turns a mild cold into a reason to see the vet. VCA reports that uncomplicated cases usually last 7 to 14 days and occasionally up to three weeks.

When to call your vet today

Call the same day if your cat has not eaten for 24 hours, if discharge from the eyes or nose turns thick and colored, if an eye is cloudy, very red or held shut, or if signs are getting worse after a few days instead of better. Kittens, senior cats and cats with other illnesses should be seen sooner, because VCA notes that young, unvaccinated and chronically ill cats are most likely to become seriously ill.

Also call if signs have lasted more than about two weeks or keep coming back. Persistent or recurring cases may need further tests, such as X-rays, blood tests or cultures, to look for a different cause or a complication.

When it's an emergency

Go to your vet or the nearest emergency vet immediately if your cat is breathing with its mouth open, breathing fast or with obvious effort, has blue or gray gums, or is collapsing. A very lethargic cat that is dehydrated and has stopped drinking also needs urgent care.

A kitten with a cold that stops nursing or eating, becomes cold to the touch or weak, needs to be seen right away, as kittens can go downhill quickly. Rarely, a severe strain of calicivirus causes high fever, swelling of the face and legs, skin sores and yellowing; Cornell describes this form as often fatal, and it needs intensive care.

What you can safely do at home

Do not give human cold or flu medicines, decongestants or pain relievers, which can be dangerous to cats, and do not use leftover antibiotics or eye drops without your vet's advice. Safe supportive care makes a real difference, though. VCA suggests sitting with your cat in a steamy bathroom for 10 to 15 minutes several times a day to loosen congestion, and gently wiping the eyes and nose with a soft, damp tissue or cotton pad.

Offer strong-smelling, tasty canned food to tempt a cat whose sense of smell is blocked; Cornell's Baker Institute also suggests soft, smelly food and humidifiers. Keep fresh water close by, provide a warm, quiet resting place, and keep the sick cat away from other cats, with its own bowls and litter box. Wash your hands after handling it.

What the vet will likely check

Most upper respiratory infections are diagnosed from the signs and a physical exam, including a check of the eyes for ulcers, the mouth for sores and the chest for any sign that the infection has spread to the lungs. VCA notes that testing to identify the specific cause is mainly advised for breeding cats, shelter outbreaks, or cats that are not responding to treatment.

Treatment is mostly supportive. Depending on what your vet finds, it may include eye medicine for discharge or ulcers, antibiotics to treat or prevent a bacterial infection, antiviral medicine in some herpesvirus cases, and medicines for pain or appetite. Cats that are dehydrated or very unwell may be hospitalized for fluids and nursing care.

Prevention

The core vaccines protect against feline herpesvirus and calicivirus. VCA and Cornell both stress that the vaccines reduce how sick cats get and shorten illness but do not always prevent infection completely. Cornell notes that kittens need a series of doses until after 16 weeks, followed by boosters on a schedule your vet sets based on your cat's risk.

Isolate any new cat for one to two weeks and have it examined before it meets your others, and keep sick cats separate. Clean bowls and surfaces regularly; Cornell notes that phenol-based cleaners are toxic to cats, so ask your vet which disinfectant to use. Reducing stress helps cats that carry herpesvirus avoid flare-ups. These infections are species-specific, and VCA describes the rare spread to people as extremely uncommon.

This page is general information, not veterinary advice, and it cannot replace an examination by the vet who knows your pet.