Upper Respiratory Infections in Cats

Upper respiratory infections, often called URIs, are among the most common infectious illnesses in cats. They affect the nose, sinuses, throat, and eyes more than the lungs. Many pet parents notice sneezing, watery or goopy eyes, nasal discharge, congestion, and a drop in appetite because cats rely heavily on smell to want food. In many cases, the illness is self-limiting, but that does not mean every cat should be watched at home without guidance from your vet.

The most common infectious causes are feline herpesvirus-1 and feline calicivirus. Other organisms, including Chlamydia felis, Bordetella bronchiseptica, and Mycoplasma species, may contribute, especially in shelters, catteries, or multi-cat homes. Stress, crowding, poor ventilation, young age, advanced age, and immune compromise can all make infection more likely or more severe.

A URI can look mild at first and still become a bigger problem if a cat stops eating, becomes dehydrated, develops a corneal ulcer, or progresses to lower airway disease or pneumonia. Kittens are especially vulnerable because congestion can quickly interfere with nursing and hydration. Cats with chronic herpesvirus may also have flare-ups during stressful times, even after the first infection has passed.

Vaccination helps reduce severity and spread, but it does not prevent every infection. That is why a vaccinated cat can still get sick, though signs are often milder. The goal is not one single treatment path. Instead, your vet will match care to your cat’s age, symptoms, exam findings, and home situation.

Many cats with upper respiratory infections are diagnosed based on history and a physical exam. Your vet will look at the eyes, nose, mouth, hydration status, temperature, and breathing effort. They may listen to the chest to make sure the problem appears limited to the upper airway and has not moved into the lungs.

If your cat is very young, older, repeatedly sick, or more ill than expected, your vet may recommend additional testing. This can include FeLV and FIV testing, blood work, and chest radiographs if pneumonia is a concern. Swabs for PCR testing or culture may be used in complicated, severe, shelter-associated, or non-responsive cases to help identify likely pathogens.

Advanced workups are not necessary for every cat. A straightforward viral URI in an otherwise healthy adult cat may be managed without a long list of tests. On the other hand, chronic congestion, one-sided nasal discharge, facial swelling, or repeated relapses may push your vet to look for other problems such as nasal polyps, dental disease, fungal infection, foreign material, or a mass.

Diagnosis is also about ruling out emergencies. A cat with noisy breathing from congestion is different from a cat with true respiratory distress. If there is any concern about oxygen levels, lower airway disease, or severe dehydration, your vet may recommend same-day treatment and monitoring.

Most feline URIs are caused by infectious organisms spread through saliva and eye or nasal secretions. Feline herpesvirus-1 and feline calicivirus are the leading causes. Cats can catch these infections through direct contact with sick cats or through contaminated bowls, bedding, litter boxes, carriers, and human hands or clothing after handling infected cats.

Bacterial organisms such as Chlamydia felis, Bordetella bronchiseptica, and Mycoplasma species may cause disease on their own or complicate a viral infection. In crowded environments, these pathogens can move quickly. That is why shelters, foster networks, breeding catteries, and multi-cat households often see clusters of sneezing and eye discharge.

Risk is higher in kittens, senior cats, brachycephalic breeds, and cats with immune system problems. Cats with feline leukemia virus or feline immunodeficiency virus may have a harder time clearing infection. Stress also matters. Boarding, moving, introducing a new pet, surgery, poor ventilation, and overcrowding can all trigger illness or herpesvirus flare-ups.

Not every cat with upper respiratory signs has a routine URI. Chronic or severe signs can also be linked with fungal disease, nasal polyps, dental disease, foreign bodies, or less common infections. That is one reason recurring symptoms deserve a veterinary exam rather than repeated guesswork at home.

Vaccination is one of the most useful tools for reducing the impact of feline upper respiratory disease. Core feline vaccines include protection against feline herpesvirus-1 and feline calicivirus as part of the FVRCP series. Vaccinated cats can still get infected, but illness is often milder and less likely to become life-threatening. Your vet can help tailor a vaccine schedule to your cat’s age, lifestyle, and exposure risk.

Good infection control matters too. If one cat in the home is sick, separate food bowls, litter boxes, bedding, and grooming tools can help reduce spread. Wash hands after handling the sick cat, and clean surfaces regularly. Stress reduction also matters because herpesvirus can reactivate during stressful periods.

Cats in shelters, foster homes, boarding settings, or multi-cat households may need more careful prevention planning. Good ventilation, avoiding overcrowding, and prompt isolation of sick cats can make a big difference. In some higher-risk environments, your vet may discuss non-core vaccines such as Chlamydia felis or Bordetella based on local risk and history.

Prevention is not only about vaccines. Routine wellness care, nutrition, parasite control, and early attention to sneezing or eye discharge all support better outcomes. If your cat tends to flare during stressful events, ask your vet how to plan ahead before boarding, travel, or introducing a new pet.

The outlook for most cats with an uncomplicated upper respiratory infection is good. Many improve within one to three weeks, especially with supportive care and monitoring. Mild viral infections may resolve on their own, but cats that stop eating, become dehydrated, or develop eye complications can need more active treatment.

Recovery is not always a straight line. Feline herpesvirus can remain in the body after the first infection and reactivate later, especially during stress. That means some cats have occasional flare-ups of sneezing, eye discharge, or congestion even after they seemed fully recovered. Chronic nasal inflammation can also linger in some cats.

Prognosis becomes more guarded when there is pneumonia, severe corneal disease, marked dehydration, or underlying immune compromise. Kittens, senior cats, and brachycephalic cats deserve closer follow-up because they can worsen faster. Cats with repeated or one-sided nasal signs may need a broader workup to find an underlying cause.

The best recovery plans are practical and individualized. Some cats do well with home care and a recheck. Others need medications, fluids, or hospitalization. Your vet can help you choose the level of care that fits both your cat’s medical needs and your household realities.