Last month I had the incredible good fortune to meet, fall in love with, and ultimately adopt a sweet, tiny, smart-as-a-whip calico kitten who now goes by the name of Piper (more about her in a future post). Rescued from a kill shelter by a local rescue group, Piper came into my life with impeccable manners, a loving disposition, and an impossibly loud purr that, much to my delight, she uses often. However, like many kittens who spend time in a shelter environment, she also came with an additional bonus – a brewing upper respiratory infection.
Upper respiratory infections in cats are highly contagious, and are found most often in environments where 1) there are large numbers of cats together in close proximity, and 2) the environment is stressful. This is why they are so common in animal shelters, cat breeding facilities, and feral cat colonies. Once cats are exposed, the illness can lie dormant in their bodies until a stressful event triggers it to let loose.
These illnesses are often referred to as “kitty colds” or “cat flu”, which tends to give the impression that, like human colds, they really aren’t all that serious. However, in young kittens, unvaccinated cats, or those with a compromised immune system, they can have serious and long-lasting consequences.
What Causes Upper Respiratory Infections In Cats?
Upper respiratory infections, or URIs, can be caused by several different organisms (sometimes more than one at the same time), which is what makes them so tricky to diagnose.
The vast majority (over 90%) of URIs are the handiwork of 2 viruses:
Feline herpes virus (FHV)
Formerly known as “Feline viral rhinotracheitis”, FHV causes typical flu-like respiratory symptoms. Like all herpes viruses, FHV stays in the body long after the cat has recovered, and can reappear months or years later. It is so common that some researchers believe approximately one-third of all cats are carriers of this virus.
Feline calicivirus (FCV)
Calicivirus causes the usual respiratory symptoms, but in addition can cause extremely painful, ulcerating sores on the gums, tongue, lips, and nose. This is a tough little virus that’s difficult to kill. Cats with calicivirus can remain contagious for months after recovery. In most cases, calicivirus eventually leaves the body, but some cats can remain carriers for life.
Other organisms that can cause upper respiratory infections in cats include the parasitic bacteria mycoplasma, chlamydia, and bordetella.
Fortunately, these organisms are only contagious to other cats – they can’t be spread to humans or to other pets in the household.
How Are Upper Respiratory Infections Spread?
There are several ways cats can become infected with upper respiratory viruses:
- Direct exposure to the saliva, secretions from the nose or eyes, and possibly the urine and feces of an infected cat. Exposure can occur through sneezing and coughing, mutual grooming, napping together in close quarters, even hissing or spitting.
- Indirect exposure from viruses hitching a ride on toys, food and water bowls, bedding, grooming tools, litter boxes, and human hands and clothing.
- Exposure to cats who are carriers and are actively shedding the virus. Carrier cats harbor the virus in their bodies, and can “shed” the virus (release it back into the environment) even if they are not showing any signs of illness. Viral shedding can be triggered by any stressor, including moving to a new home, injury or illness, or the addition of a new family member (baby, dog, or another cat) to the household.
Symptoms Of URIs
Once a cat becomes infected with one of these microorganisms, symptoms generally show up within 2-10 days. They can include:
- Nasal discharge (either clear and thin, or thick and colored brown, green, or yellow)
- Conjunctivitis (inflammation of the eyes, causing discharge and/or squinting)
- Loss of appetite
- Lack of energy
Severity of these signs can vary considerably. In some cats (like Piper), they can be very mild and don’t last for long, but in other cases they can be quite severe and last for weeks.
Below is a photo of Piper during the worst part of her illness. Fortunately, she only had conjunctivitis in one eye, no nasal discharge, and very mild sneezing.
Piper was lucky; by the time she was exposed to the virus she had already started her vaccination series, which undoubtedly helped lessen the severity of her symptoms. Some kittens with URIs can become very sick, like this poor baby:
In the most severe cases, upper respiratory infections can cause coughing, drooling, painful corneal ulcers on the surface of the eye, and the aforementioned ulcers in the mouth and nose.
Why Are Upper Respiratory Infections In Cats So Hard To Treat?
Upper respiratory infections are notoriously difficult to treat and manage, for several reasons:
- They can be caused by many different types and strains of viruses and bacteria, and diagnosing which microorganism is the culprit is extremely difficult. There is no one simple test that can be run, so diagnosis is usually based purely on clinical symptoms.
- Most (over 90%) are caused by viruses, so antibiotics have no real effect other than to help prevent secondary bacterial infections.
- There is no way to determine if or when an infected cat is no longer contagious.
- Viruses can remain active and infective for up to 10 days on surfaces, and in the case of calicivirus, the only thing that will kill it is bleach solution. This makes it virtually impossible to disinfect all areas the cat has come into contact with.
- Some cats who are carriers remain so for life, and can experience repeated flare-ups of symptoms over the course of their lifetimes. There is currently no test available to determine if a cat is a carrier.
What You Can Do If Your Cat Develops An Upper Respiratory Infection
If your kitty develops an upper respiratory infection, know that the average illness typically lasts between 7 and 14 days, regardless of treatment. Since most of these infections are viral, antibiotics usually aren’t much help (and in some cases, may make the kitten or cat feel worse by causing digestive system upset).
Treatment for URI is generally based on providing supportive care and relief from symptoms while your kitty’s body fights the virus. However, if your kitten is very young, or you notice coughing, severe eye squinting, extreme weakness, or a refusal to eat, call your veterinarian immediately for advice.
For milder cases, here are things you can do to help nurse your kitten or cat through a URI.
- If you have multiple cats, separate the sick cat immediately and give her a warm, comfortable “quarantine” room, away from noise and drafts.
- Use a soft cotton ball soaked in warm water to wipe away any discharge from the eyes and nose. This prevents skin irritation, helps keep the nose clearer for breathing, and generally seems to make cats feel better.
- Offer soft, wet food (preferably with a strong smell) that has been warmed up to encourage your cat or kitten to keep eating. Cats with URIs are often unable to smell their food due to nasal congestion, which causes them to lose their appetite. Good nutrition and steady caloric intake will help them recover faster.
- If your cat is extremely congested and has difficulty breathing, use a humidifier or vaporizer to add moisture to the room. You can also take your cat into the bathroom, close the door, and run hot, steamy water in the shower.
- Keep your cat warm. This is especially important for kittens, who can’t efficiently regulate their body temperatures and can easily become chilled.
- Ask your veterinarian about giving your cat L-lysine, an amino acid that is thought to help boost the immune system by interfering with herpes virus reproduction in the body. Although there is still some debate as to whether L-lysine actually works, many cat parents and veterinarians have reportedly used it with good success.
- Keep your cat playing. Although your first instinct may be to try to keep your cat quiet at all times, short, gentle play sessions can actually help get your cat’s circulation going and improve her mood. I noticed this with Piper – she seemed to perk up quite a bit after playing for just a few minutes at a time. Just be careful not to overdo it.
For more serious cases, your veterinarian can prescribe antiviral medications or eye drops, decongestants, and immune supplements. Keep your veterinarian informed of your kitty’s progress, and don’t hesitate to call them if your cat or kitten is not improving or takes a turn for the worse.
Upper Respiratory Infections In Cats – S’not A Fun Experience
So how serious are these infections?
Upper respiratory infections can last anywhere from 1 to 4 weeks, and most cats and kittens fully recover. However, very young kittens, older cats, cats who have never been vaccinated, and those with a suppressed immune system (such as cats with FeLV or FIV) can develop life-threatening complications, including malnutrition (from being unable to eat), dehydration, and pneumonia. Permanent eye damage from corneal ulcers can cause blindness, and sometimes surgery is required to remove the damaged eye. Cats who remain carriers of the virus may experience occasional symptom outbreaks during times of stress, but these recurrences can usually be managed.
Since it’s virtually impossible to prevent your cat from being exposed to upper respiratory viruses, you can help lessen her chances of becoming sick by making sure she receives at least an initial round of FVRCP vaccinations. Although the vaccines may not completely prevent her from contracting the virus, they can help lessen the severity of the symptoms if she does become ill. Also, consider keeping your cat inside full-time and away from other potentially infected cats.
Although they are common, and most cats recover without long-term health effects, upper respiratory infections should never be taken lightly. It’s always better to err on the side of caution and talk to your veterinarian if you have any concerns during your cat’s illness and recovery from a URI.
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Has your cat ever experienced an upper respiratory infection? Please share your story with us in the comments below!