Upper Respiratory Tract Infection in Cats: Symptoms, Treatment and Recovery
Your cat sneezes once. Then five times. By evening there is crust around one eye and a snuffly little snore you have never heard before. Sound familiar?
An upper respiratory tract infection in cats is one of the most common reasons owners call the vet. Most cases are mild. Some are not. This guide covers the early signs, what treatment really involves, what it costs, how long it lasts, and what actually helps at home.
What Is an Upper Respiratory Tract Infection in Cats?
Vets call it feline upper respiratory disease. Owners call it cat flu or a cat cold. It is an infection of the nose, throat, sinuses, and eyes. Yes, cats can get upper respiratory infections, and they get them often, especially in multi-cat homes, shelters, and catteries.
Two viruses cause the bulk of cases: feline herpesvirus-1 and feline calicivirus. Trudell Animal Health puts them behind roughly 90% of cases. Bacteria such as Chlamydia felis, Mycoplasma, and Bordetella bronchiseptica can cause infections too, or pile onto a viral one.
How does a cat get an upper respiratory infection?
Through contact. Sneezing, shared bowls, shared litter boxes, grooming each other, even your hands after petting an infected cat. Stress is the quiet trigger. Herpesvirus stays in the body for life once a cat is infected, and a move, a new pet, or boarding can flare it up again.
Prevalence of feline calicivirus across eight California shelters in a study of 573 cats by Bannasch and Foley. Herpesvirus ranged from 3% to 38%. The same research notes URIs are a leading cause of shelter euthanasia.
Upper Respiratory Tract Infection Symptoms in Cats
Early signs are easy to miss. Watch for these first:
- Sneezing, often in clusters
- Clear, watery discharge from the nose or eyes
- Squinting or a swollen third eyelid
- Reduced appetite (cats depend upon their noses in order to smell food, which leads to decission - whether food will be eaten or skipped, so a blocked nose means a skipped meal)
- Mild lethargy or hiding
As the infection moves along, discharge turns thick and yellow or green. You may see mouth ulcers, drooling, a raspy voice, or a low fever. Upper respiratory tract infection symptoms in kittens hit harder and faster. Their small airways clog quickly and they dehydrate fast.
When should I worry about my cat's upper respiratory infection?
Sniffles alone in a bright, eating adult cat can often be watched for a day or two. Anything on the right side of this table means call the vet.
| Watch at home (24 to 48 hours) | Call the vet today |
|---|---|
| Occasional sneezing | Not eating for 24 hours or more |
| Clear eye or nose discharge | Thick yellow or green discharge |
| Normal energy and appetite | Open-mouth breathing or labored breathing |
| Drinking normally | Mouth ulcers, heavy drooling, eye cloudiness |
| Adult cat in good health | Any kitten, senior, or immune-compromised cat |
A cat that skips meals for more than a day risks hepatic lipidosis, a serious liver condition. That is why appetite is the signal that matters most.
Feline Upper Respiratory Tract Infection Treatment
Here is the honest truth. There is no cure for the viruses themselves. Treatment aims to keep your cat comfortable and eating while the immune system does the work. That is why a vet visit still matters: it separates a simple viral cold from a bacterial infection or something else entirely, like asthma or a nasal foreign body.
What vets prescribe
If bacteria are involved, vets commonly use doxycycline or amoxicillin-clavulanate. Eye ointments handle conjunctivitis. In stubborn herpesvirus cases, some vets add an antiviral. Fluids and appetite support help cats that are dehydrated or refusing food.
Can you buy effective cat medications for upper respiratory infections online? Only through a vet. Antibiotics and antivirals need a prescription, and the wrong drug or an unfinished course makes the next infection harder to treat. Reputable online pharmacies fill your vet's prescription. They do not replace the exam.
What does it cost?
Catster's cost guide lists an average of about $219 for diagnosing and treating a URI. Your bill depends on your region, whether the vet runs a respiratory PCR panel to identify the pathogen, and whether your cat needs fluids or hospitalization. Most accident and illness pet insurance plans cover URIs. Check waiting periods and pre-existing condition rules before you enroll, since recurring cat flu can be flagged.
Home care that actually helps
- Warm up wet food slightly. Stronger smell, more interest.
- Run a cool-mist humidifier, or sit with your cat in a steamy bathroom for 10 minutes.
- Wipe eyes and nose gently with a warm, damp cloth, one fresh cloth per eye.
- Keep water bowls fresh and nearby.
- Skip essential oil diffusers. Many are toxic to cats.
- Never use human decongestant sprays. Ask your vet about saline drops or a veterinary-approved nasal spray.
Air purifiers with HEPA filters can cut dust and airborne irritants that keep a stuffy cat miserable. They will not stop one cat from infecting another, so isolation still matters.
The supplement question, answered straight
L-lysine was recommended for cats with herpesvirus for years. The evidence did not hold up. A 2015 systematic review by Bol and Bunnik in BMC Veterinary Research found no support for lysine preventing or treating feline herpesvirus, and some studies saw worse disease in cats receiving it. If a product leads with lysine as a cure, be skeptical.
What nutrition can do is support general health: healthy weight, good hydration, balanced fatty acids, and a diet your cat will actually eat while recovering. Ask your vet whether a recovery diet or an immune-support supplement makes sense for your cat.
How Long Does a Cat URI Last, and How Contagious Is It?
After exposure,symptoms normally appear between 2 to 10 days and last 7 to 10 days. Complicated cases can drag out to 3 weeks. Kittens and older cats take longest.
Contagious? Very. Cats shed virus through eye, nose, and mouth secretions, sometimes before symptoms show and for weeks after they fade. Herpesvirus lasts for life, so some cats flare up again under stress. Calicivirus carriers can shed for months. Keep a sick cat in a separate room, wash your hands between cats, and give each cat its own bowls and litter box during illness.
What about people and dogs? Cat flu viruses do not spread to humans or dogs. The exception is Bordetella bronchiseptica, the bacterium behind kennel cough. International Cat Care classes it as a rare zoonosis, mainly a concern for people with weakened immune systems.
Preventing the Next Infection
Vaccines help, but they are not a force field. The core FVRCP vaccine covers herpesvirus and calicivirus. It will not always stop infection. It does make symptoms milder if your cat catches something. Kittens start the series at 6 to 8 weeks, then follow with boosters.
After an infection, clean the environment. Wash bedding in hot water with detergent. Wash toys and bowls. For hard surfaces, calicivirus resists many disinfectants, so ask your vet about a diluted bleach solution (a 1:32 ratio is the common guideline), rinse well, and keep your cat out of the room until it dries.
The Bottom Line
Most feline upper respiratory tract infections clear up in about a week and a half with rest, food, humidity, and a vet's guidance. The ones that need urgent care announce themselves through appetite loss, labored breathing, or a very young or very old patient. When in doubt, call.
Keep vaccines current, keep stress low, and keep the supplement shelf honest. Your cat does not need miracle cures. It needs good care and a clear head on your side.
1. Omega-3 Fatty Acids for Cats: What They Do, Why They Matter, and How to Use Them
2. Best High-Protein Foods for Cats
3. Essential Vitamins and Minerals Every Cat Needs for Optimal Health
Frequently Asked Questions
constantly sneezing, watery eyes, and a running nose are usually first. A drop in appetite often follows. If your cat also seems tired or is squinting, book a vet visit.
Most last 7 to 10 days. In Complicated cases, kittens, and senior cats can take up to 3 weeks. Herpesvirus can flare again later in life.
Yes, very. It spreads through sneezing, shared bowls, and grooming. Cats can shed virus for weeks after symptoms fade, so keep a sick cat separated.
The common cat flu viruses cannot. The bacterium Bordetella bronchiseptica can infect dogs and, rarely, people with weak immune systems. Wash your hands after touching a sick cat.
Mild viral cases in healthy adult cats often do. Kittens, seniors, and cats that stop eating should not be left to wait it out. Bacterial infections need antibiotics.
Catster's cost guide lists about $219 on average. Testing, fluids, and hospitalization raise the total. Insurance often covers it, subject to waiting periods.
Yes. The core FVRCP vaccine protects against herpesvirus and calicivirus. It reduces how sick a cat gets but does not guarantee your cat will never catch it.