One day your cat is totally normal, and the next day you start to hear tiny little sneezes. Soon there is yellow mucus coming from your cat’s nose and runny watery eyes. These are symptoms of a cat cold.
The cat cold represents the number one health problem affecting cats in shelters and recently adopted cats from shelters. Two viruses: feline herpesvirus and feline calicivirus account for the majority of colds in cats. Cats can be lifetime carriers of these viruses and when they are stressed their virus can become activated and cause cold symptoms.
L-Lysine is a supplement that can reduce the length of time a cat has a cold from herpes virus and reduce the amount of virus a cat will shed. A yummy powder formula that is highly rated is available on Amazon that you can mix into your cat’s food. Check it out here.
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Solitary, indoor only cats which catch colds
If you have an only-cat at home you may be puzzled how your cat caught a cold.
Stress is the number one trigger for reactivating latent upper respiratory viruses like feline herpes virus. It may not always be obvious what a stress-trigger could be. Simple things like changes in furniture arrangements, a visitor to the home, pet owners going on vacation, outdoor animals such as stray cats wandering near the home all can trigger a stress response in your cat. The Ohio State Indoor Pet Initiative is a great resource to help cat owners provide a happy home for their feline friend. https://indoorpet.osu.edu/cats
It may surprise you to adopt a healthy cat or kitten from a shelter and have them come down with an upper respiratory infection a few days later. This is often because the cat was exposed to a virus or bacteria at the shelter and it took a few days to develop symptoms. For example, Calici virus is present in up to 90% of cats housed in larger groups and can take 2-6 days to show symptoms of infection.
How to know if your cat has a cold. Symptoms can include:
Local signs
- Congestion
- Watery eyes
- Yellow discharge from the eyes
- Rust colored eye discharge
- Red tears
- Conjunctival swelling
- Tongue ulcers
- Squinting
- Sneezing
- Clear or colored (yellow) mucus
- Coughing
- Stertor
- Stridor
Systemic signs
- Lethargy
- Decreased appetite
- Fever
- Limping
Read on to learn more about cat colds and how to treat and prevent future colds
How long do cat colds last?
Most cat colds resolve in 7 to 10 days. It is uncommon for a cat cold to take longer than 10 days to resolve. Occasionally some cats in shelters are unable to fully clear their infection due to stress from their environment. However, cats will often clear their infection once adopted.
Most common causes of colds in cats
The most common causes of upper respiratory tract infections in cats are due to viruses or bacteria. However, 80 to 90 percent of cat colds are due to one of two viruses: Feline Herpesvirus-1 (FHV-1) and Feline Calicivirus (FCV).
Transmission of feline upper respiratory viruses
Surprisingly, aerosol transmission is NOT a significant cause of transmission. Rather, viral transmission occurs most commonly by transfer of virus on fomites (virus spread on blankets, food and water dishes, unwashed human hands, etc.) and via droplet transmission from an infected cat sneezing or coughing within 5 feet of another cat.
Feline herpes virus is ubiquitous and up to 97% of cats will be exposed to this virus in their lifetime. Up to 80% of exposed cats will be infected lifelong and up to 45% of these cats will periodically show symptoms of the virus when stressed. Young and adolescent cats are most susceptible to this infection.
Cats that live alone and come down with a cold most likely reactivated herpes virus that was dormant within their body
Calicivirus is also a highly contagious respiratory virus of cats. Up to 90% of cats in shelters are infected. Most cats will show symptoms of an upper respiratory infection. More rarely, cats will develop pneumonia. Another rare complication of feline Calici are tongue ulcers and limping. A very very rare form of the virus will cause multi organ damage and can be fatal.
Testing for feline upper respiratory viruses and bacteria
Upper respiratory viruses in cats can be diagnosed via a swab sample of the oropharynx sent for PCR testing. One of the main veterinary reference labs, IDEXX, has a Feline Upper Respiratory Disease RealPCR Panel that test for feline herpes virus, feline calicivirus, Chlamydophila felis, Mycoplasma felis, Bordetella bronchiseptica and H1N1 influenza virus. This test requires a deep swab in the back of the throat and a conjunctival swab.
Bacterial causes of colds in cats
Bacterial causes of colds in cats are caused mainly by Chlamydophila felis, Mycoplasma and Bordetella bronchiseptica.
Chlamydophila is a specific bacteria of cats that likes to replicate in the conjunctiva (pink tissue surrounding the eyes). Chlamydophila mainly causes eye discharge, redness and swelling of the pink tissues that line the eye. It mainly affects young kittens and causes severe swelling, redness and yellow eye discharge. It can occasionally cause sneezing and clear nasal discharge. The bacteria does not survive for long in the environment so transmission is primarily from direct contact between cats. Thirty percent of cats with long term conjunctivitis have chlamydophila infections.
To learn more about how to diagnose and treat eye infections in cats, read this article
Diagnosis of chlamydophila can be made via PCR from a swab of the conjunctiva . It is treated with tetracycline antibiotics.
Mycoplasma bacteria commonly reside in the upper airways of cats but sometimes these pathogens can lead to cold symptoms. In a study of shelter cats, this bacteria was the most commonly isolated bacteria of cats with upper respiratory signs. The bacteria can be identified from a swab from the nose or the back of the mouth (oropharynx). Mycoplasma bacterial infection in cats can cause nasal discharge (clear to yellow), sneezing and conjunctivitis. A tetracycline antibiotic like doxycycline is a very good antibiotic treatment choice for this infection.
Bordetella bronchiseptica in cats typically only occurs in cats housed together, not in cats in small groups or solitary cats. The disease causes mild sneezing, coughing and discharge from the nose and mouth. Very rarely the bacteria can cause severe infection with pneumonia, but this is most often only in kittens.
Prevention of colds in cats
Prevention of colds in cats centers around reducing household stress and also providing proper vaccination.
Ways to please your cat and reduce stress
Provide vertical resting spaces. Cats love to perch up high to survey their territory . Cat trees and perches on tall furniture are all good examples of vertical space options.
Use a feliway diffuser in the home. Feliway is a calming feline pheromone that induces relaxation in cats. Feliway Multicat is best suited for reducing anxiety triggered by intercat aggression.
Keep litter boxes clean and placed in areas that are quiet and not heavily trafficked. If a litter box is near a loud air conditioning unit or space where there is a lot of foot traffic it may be a source of anxiety for your cat. You should ideally have one more litter box than the number of cats in the home. Ample litter boxes helps to avoid litter box guarding and intercat aggression around the litter box.
Provide calming supplements. Purina makes a calming probiotic supplement you can use for your cat. Probiotics seed the GI tract with beneficial bacteria. The bacterial composition of your intestinal tract has a proven impact on mental health. Purina Calming Care probiotic uses a strain of bacteria that has been documented to reduce anxiety in cats. The probiotic also helps to reduce sneezing in cats with herpes virus and cope with changes in the household. It promotes behaviors such as playing and seeking attention for owners: behaviors that indicate a happy cat.
Zylkene is another good calming supplement for cats. It comes as a capsule that can be opened up over food. It is tasteless and easy to hide in food. The active ingredient is a cow milk protein alpha-casozepine.
Make sure your cats are vaccinated
Vaccination unfortunately does not prevent infection but does reduce severity and duration of cold symptoms. It also greatly reduces viral shedding which makes transmission to other cats less likely.
Modified live vaccines are available to protect against herpes virus, feline calicivirus and feline panleukopenia virus (FVRCP vaccine). This is considered a core vaccination for cats. Two vaccinations 2-3 weeks apart are required for protection. Kittens are vaccinated starting at 6 weeks and are re-vaccinated every 2 weeks in shelters until they are 18 to 20 weeks of age. In less high-risk environments (a single family home for example) kittens are vaccinated at longer intervals of every 3-4 weeks until they are 16 weeks or older. The vaccine is then recommended to be updated every 3 years.
What do you do for a cat that has a cold?
Most cat colds will resolve in 7 to 10 days. If your cat is sneezing and congested but still eating well and acting normally you can just wait for the cold to run its course.
Sometimes cats with colds will need to get treatment from a veterinary visit. You should seek treatment for your cat if you notice symptoms of lethargy and decreased appetite, squinting, yellow nasal or ocular discharge or any signs of trouble breathing. You can try taking your cat’s temperature at home to see if your cat has a fever. A normal temperature in a cat is 99 to 102.5. Fevers in the 103 range do not generally make cats feel too sluggish. However, if the fever rises to above 104 degrees you will usually notice your cat is lethargic and may not be eating well.
Here is a video from iCatCare that demonstrates how to take your cat’s temperature:
Kittens are most susceptible to fevers and lethargy from upper respiratory infections. Your veterinarian may choose to prescribe an antibiotic if there is a fever or yellow discharge from the nose or eyes which indicates a secondary bacterial infection.
Lysine is an amino acid that is used for herpes virus flare ups. It stops and reduces viral replication by inserting the wrong amino acid base pair into the DNA of herpes virus. Studies have shown supplementation with oral lysine significantly reduced herpes virus shedding and fewer cats developed conjunctivitis. Lysine is dosed at 500mg per day for an adult cat and 250mg per day for a kitten. It can be purchased as a powder you sprinkle on food, a gel, or as a treat. Check out this Lysine product available from Amazon that is a lysine powder that is liver flavored and highly rated.
Chronic or relapsing cold symptoms in cats
Some cats unfortunately suffer from recurrent eye infections (chronic conjunctivitis) or recurrent sneezing/nasal discharge called chronic rhinitis. Cats with recurrent conjunctivitis may be prescribed antiviral medication in the form of antiviral eye drops or an oral antiviral medication.
Chronic rhinitis is notoriously difficult to treat and may be best managed with an internal medicine specialist. Chronic rhinitis is a cat with chronic nasal congestion symptoms that persist for longer than 1 month. These cats are coined chronic “snufflers”.
Cats with chronic rhinitis should be evaluated carefully for an underlying issue causing persistent signs
Possible causes of persistent nasal congstion in cats are :
- Nasopharyngeal polyps
- Narrowed/strictured area in the nasal passages
- Foreign material in the nasal passages
- Cancer
- Tooth root infections
Nasopharyngeal polyps are typically found in young cats and arise from the Eustachian tube or the middle ear. These can be visualized with a good ear exam with an otoscope cone, or sometimes with a sedated oral exam to reflect the soft palate if the polyp has grown there. Polyps are typically a fleshy mass on a long stalk. The polyp can be removed by traction. If the polyp returns, then a surgery to remove the material in the bulla of the ear is indicated. This procedure is called a bulla osteotomy.
Narrowed nasal passages can occur as a congenital condition but are very rare. It could be identified with imaging of the nasal passages with a CT or rhinoscopy. Rhinoscopy is a fiber optic guided camera that can be inserted into the nose. Rhinoscopy equipment can remove foreign material or biopsy tissue that appears abnormal.
Foreign material in the nasal passages or cancer would be best identified with imaging as well with either a CT or rhinoscopy.
Tooth root abscesses can be a cause of upper respiratory symptoms, but it is still rare that it will cause nasal discharge. If nasal discharge is present from a tooth root abscess it is generally unilateral on the side of the affected tooth. This can be diagnosed with sedated x rays of the mouth.
Some cats with chronic inflammation and destruction of the nasal turbinates (the scrolls of bone inside the nose) may benefit from periodic sedated nasal flushes to remove built up debris and mucus.
Cats can get the flu, but this is a very rare cause of upper respiratory signs
Cats are susceptible to flu viruses like the avian flu, but it is not documented often. Perhaps this is because their symptoms are often mild and they are not presented to the veterinarian for this diagnosis.
Are cat colds contagious to humans or can cats catch colds from people?
There are reports of people transmitting the seasonal flu to their cats, but this is still uncommon. The risk of you contracting the flu from your cat is low. Transmission of flu to cats is the same as it is for people: direct contact (sleeping, playing, sharing food/water), airborne via droplets from sneezing and coughing and via fomites ( blankets, bedding, bowls, hands etc that are carrying the virus).
Summary of indoor cats with colds
Most cats have been previously exposed to the two major upper respiratory viruses that cause cold symptoms in cats. Some cats can be lifelong carriers of these viruses and shed the virus intermittently. Cold signs can vary from ocular and or nasal discharge with and without systemic symptoms of lethargy, fever and decreased appetite. Stress plays a major role in recrudescence of symptoms and indoor cats. There are a number of environmental changes and supplements that promote wellenss indoor cats.
