Upper Respiratory Infections in Cats: Symptoms and Treatments

If you’re a cat owner, you know how important it is to keep your feline friend healthy and happy. Unfortunately, one of the most common health issues cats face is upper respiratory infections caused by viral rhinotracheitis or chlamydophila felis. These infections can affect the nasal passages, throat, and bronchi, leading to clinical signs such as nasal congestion, discharge, breathing difficulties, and inflamed mucous membranes.

Upper respiratory infections in cats, classified as infectious diseases, are particularly dangerous for young kittens and cats. Their immune systems are not fully developed yet, making them more vulnerable to infectious agents.

Common causes of these infections include feline herpesviruscalicivirus, Bordetella bronchiseptica bacteria, and fungal infections like Cryptococcus neoformans. The incubation period for these infectious diseases can vary depending on the specific agent causing the infection. Therefore, veterinary medicine is crucial in diagnosing and treating cat infections.

Suppose you’ve noticed your cat experiencing clinical signs like nasal congestion or discharge. In that case, they may have an upper respiratory infection caused by infectious diseases such as feline herpes virus. Breathing difficulties and drainage may also occur. But what exactly is an upper respiratory infection? Keep reading to find out more.

Symptoms of Upper Respiratory Infections in Cats

Upper respiratory infections (URIs) are common in cats and can cause various clinical signs. These infections, often caused by feline herpes virus, affect the cat’s nose, throat, and sinus areas, resulting in nasal drainage. The symptoms can be mild or severe, depending on the severity of the infection, and may even lead to the development of ulcers.

Common Symptoms

Cats’ most common feline upper respiratory infection (URI) symptoms include sneezing and coughing, usually caused by respiratory tract infections. These respiratory signs are often associated with the feline herpes virus. Cats with URIs may also have a runny nose or discharge from their eyes, called conjunctivitis.

Clinical Signs

In addition to these common symptoms, other clinical signs may indicate an upper respiratory infection in cats. These include feline herpes virus, nasal drainage, eye discharge, and disease.

  • Nasal discharge: This can be clear or colored.
  • Conjunctivitis: This is inflammation of the eye lining.
  • Fever: A high body temperature can indicate an infection.
  • Loss of appetite: Cats may not want to eat due to congestion or discomfort while swallowing, which can be caused by feline upper respiratory infection, herpes virus, or respiratory signs similar to the common cold.
  • Lethargy: Cats with respiratory tract infections such as feline herpes virus or common cold may exhibit respiratory signs and appear tired or less active than usual.

Respiratory Signs

Cats with more severe URIs may experience respiratory signs such as wheezing and difficulty breathing. This can be especially concerning for kittens, elderly cats, or those with pre-existing respiratory conditions. Feline herpes virus is a common cause of this disease, and the prognosis may vary depending on the severity of the infection.

It is important to note that some cats may not show signs of herpes when they have an upper respiratory infection. However, they can still spread the virus to other cats through direct contact or shared objects like food bowls.

Diagnosing URIs in Cats

Veterinarians typically diagnose upper respiratory infections, commonly known as cat flu, in affected cats based on clinical signs and physical examination findings. However, susceptible cats, particularly those in crowded environments like shelters, are at a higher risk of contracting the virus. Therefore, if necessary, they may also perform tests like blood work or cultures.

If your affected cat shows any respiratory signs of a URI, it is important to bring them to a veterinarian for evaluation. Susceptible cats, especially those in shelter environments, are at higher risk, and early treatment can help prevent complications like secondary bacterial infections or pneumonia.

Upper Respiratory Infections in Cats

Causes of Upper Respiratory Infections in Cats

Upper respiratory infections (URIs) are common among cats and are caused by various factors, including viral and bacterial infections and environmental stressors that can weaken a cat’s immune system. These infections affect the nose, throat, and sinus areas of a cat’s upper respiratory system. It is important to note that viruses can also contribute to developing URIs in cats.

Viral Infections

Viral infections are the most common cause of URIs in cats, which can lead to respiratory signs and affect the respiratory tract. The feline herpesvirus (FHV-1) and calicivirus are two viruses that commonly cause URIs in cats. FHV-1 is highly contagious and can spread through direct contact with an infected cat or contaminated objects such as food bowls or bedding. Calicivirus is less contagious but still poses a significant risk to unvaccinated cats.

Bacterial Infections

Bacterial infections can also cause URIs in cats, often as a secondary infection following a viral infection. One of URIs’ most common bacterial causes is Bordetella bronchiseptica, which is highly contagious and easily transmitted between cats. These infections affect the respiratory tract and can lead to respiratory signs in cats.

Environmental Stressors

Stress and poor living conditions can weaken a young cat’s immune system, making them more susceptible to upper respiratory infections. In addition, factors such as overcrowding, poor ventilation, and inadequate hygiene practices can create an environment where bacteria and viruses thrive.

Other factors that may contribute to respiratory tract infections development and respiratory signs include age (young kittens and older cats are more susceptible), concurrent illnesses such as feline immunodeficiency virus (FIV) or feline leukemia virus (FeLV), and exposure to cigarette smoke.

Risk factors for upper respiratory infections in cats

Cats are susceptible to upper respiratory infections (URIs), which viruses and bacteria can cause. Knowing the risk factors associated with URIs in cats is important to take preventative measures and ensure your feline friend stays healthy.

Susceptible Cats

Some cats are more susceptible to URIs than others due to their respiratory tract. For example, kittens, senior cats, and those with weakened immune systems are at a higher risk of developing URIs because of their respiratory tract.

Unvaccinated Cats

Unvaccinated cats are more likely to contract URIs. Vaccines protect against some of the most common causes of URIs in cats, including feline herpesvirus and calicivirus. However, if your cat has not been vaccinated, it may be at risk of contracting these viruses and developing an infection.

Shelter Cats

Shelter cats have a greater risk of developing URIs due to the proximity of other cats. When many cats live in one place, it is easier for viruses and bacteria to spread from one cat to another. Shelters also tend to have high-stress environments that can weaken a cat’s immune system, making them more susceptible to infections.

Exposure to Stressors

Cats exposed to stressors such as overcrowding or poor nutrition are at an increased risk for URIs. Stress weakens the immune system, making it harder for the body to fight infections. Overcrowding can also increase the likelihood of exposure to infected animals.


The risk of URIs in cats can be reduced through proper vaccination and preventative care. Make sure your cat is up-to-date on all vaccinations recommended by your veterinarian. Keep their living space clean and well-ventilated, and provide a healthy diet that meets their nutritional needs. If you have multiple cats, ensure they have enough space to live comfortably and avoid overcrowding.

Contagiousness of Upper Respiratory Infections in Cats and Other Animals

Upper respiratory infections (URIs) are common in cats and can be highly contagious. URIs can easily spread from one infected cat to another, especially in environments where cats are housed together, such as animal shelters or catteries. This article discusses the contagiousness of upper respiratory infections in cats and other animals.

How Contagious Are Upper Respiratory Infections in Cats?

URIs are caused by various viruses and bacteria that affect the upper respiratory tract. The most common viral causes of URIs in cats are feline herpesvirus type 1 (FHV-1) and calicivirus. These viruses can be shed in infected cats’ nasal secretions, saliva, and tears. When an infected cat sneezes or coughs, tiny droplets containing the virus can travel through the air and infect other cats within proximity.

Cats with viral infections such as FHV-1 and calicivirus are more likely to develop respiratory disease and infect other cats. Infected cats may show symptoms like sneezing, coughing, runny nose, fever, loss of appetite, lethargy, and conjunctivitis (pink eye). Kittens and senior cats are particularly vulnerable to severe complications from URIs.

Bordetella bronchiseptica is a bacterial species that typically causes kennel cough in dogs but can also cause respiratory infections in cats. Infected kittens may develop pneumonia due to Bordetella infection.

Can Other Animals Contract URI Similar To Cat Flu?

Other animals, such as dogs, rabbits, and ferrets, can also contract URI, similar to cat flu. For example:

  • Dogs: Canine infectious tracheobronchitis (known as kennel cough) is caused by Bordetella bronchiseptica bacteria that can infect cats. Dogs living in close quarters, such as kennels, shelters, or dog shows, are at higher risk of contracting the disease.
  • Rabbits: Pasteurella multocida is a bacterium commonly found in rabbits’ mouths and respiratory tracts. It can cause respiratory infections similar to URI in cats.
  • Ferrets: Ferrets are susceptible to viral and bacterial infections affecting their respiratory system. Influenza viruses, Bordetella bronchiseptica, and Streptococcus zooepidemicus are common pathogens that can cause URIs in ferrets.

When Should You Contact a Veterinarian?

If you suspect your cat has URI or any other infectious diseases, it’s important to contact your veterinarian as soon as possible. Early diagnosis and treatment can help prevent the spread of infection to other cats and reduce the severity of symptoms.

Your veterinarian may recommend diagnostic tests like blood work, urinalysis, or culture and sensitivity testing to identify the specific pathogen causing your cat’s URI. Treatment for URIs typically involves supportive care such as antibiotics (if bacterial), antiviral medications (if viral), fluids therapy, nutritional support, and good hygiene practices.

The Severity of Upper Respiratory Infections in Cats

Upper respiratory infections (URIs) are a common health issue in cats, particularly those living in multi-cat environments such as shelters or catteries. Various viruses and bacteria can cause these infections, and their severity can vary widely depending on the specific pathogen involved.

Varying Severity of URIs

Some cats may only show mild symptoms such as sneezing, nasal discharge, and conjunctivitis. However, in other cases, the infection may progress to more severe symptoms such as fever, anorexia, lethargy, and difficulty breathing.

Severe complications such as pneumonia or even death can occur in rare cases. The severity of the infection is often related to the cat’s immune system strength and overall health status.

Importance of Early Diagnosis and Treatment

Early diagnosis and treatment are crucial for improving the prognosis of URIs in cats. If left untreated or if treatment is delayed, the infection can worsen and lead to more severe complications that may require hospitalization.

Treatment typically involves supportive care, such as fluid therapy to prevent dehydration and antibiotics to treat secondary bacterial infections. In some cases, antiviral medications may also be used.

Susceptibility Factors

Cats with weakened immune systems or pre-existing health conditions may be more susceptible to severe URIs. Kittens are also at higher risk due to their immature immune systems.

Owners should monitor their cats closely for any signs of illness and seek veterinary attention promptly if they suspect their cat has a URI. This is especially important for cats with underlying health conditions that could increase their risk for complications.

Prevention and Treatment of Feline Upper Respiratory Infections

Feline upper respiratory infections (URI) are a common problem among cats, especially those that live in shelters or multi-cat households. These infections can be caused by various viruses and bacteria, including feline herpesvirus (FHV), feline calicivirus (FCV), and Bordetella bronchiseptica. Preventing and treating these infections involves good hygiene practices, supportive care, vaccination, and antibiotics when necessary.


Preventing feline URIs starts with good hygiene practices. Cats should be kept in clean environments with access to fresh water and nutritious food. Litter boxes should be cleaned regularly, and bedding should be washed frequently. It is also important to isolate sick cats from healthy ones to prevent the spread of infection.

Vaccination against FVR and feline chlamydiosis can help prevent feline upper respiratory infections. The FVR vaccine protects against FHV-1, one of the cats’ most common causes of URIs. The vaccine for feline chlamydiosis protects against another bacterium that can cause URIs in cats.


Antibiotic therapy, known as cat flu, is commonly used to treat feline upper respiratory infections. This is because antibiotics can help control bacterial infections that often occur as secondary infections following viral cat flu. However, it is important to note that not all cases of cat flu require antibiotic therapy – only bacterial infections require antibiotics.

Supportive care is an important part of therapy for feline upper respiratory infections. This includes providing your cat adequate nutrition, hydration, warmth, and rest while they recover from their illness.

Veterinary medicine offers a range of drugs and medications for treating feline upper respiratory infections. These include antiviral medications such as famciclovir or lysine supplements, which may reduce symptoms or shorten the duration of illness caused by FHV-1. In addition, supportive care such as nebulization and humidification can help alleviate respiratory symptoms.


Diagnosing a feline upper respiratory infection, or cat flu, is usually based on clinical signs and history. URI symptoms include sneezing, coughing, nasal discharge, conjunctivitis (inflammation of the eyes), fever, and lethargy. In addition, your veterinarian may perform diagnostic tests such as blood work or culture samples to identify the underlying cause of the cat flu.

Understanding and Managing Upper Respiratory Infections in Cats

Upper respiratory infections are common among cats, and it is important to understand the symptoms, causes, risk factors, contagiousness, severity, prevention, and treatment of these infections.

Symptoms of upper respiratory infections in cats include sneezing, coughing, runny nose, watery eyes, fever, loss of appetite, and lethargy. Depending on the cat’s immune system, these symptoms can be mild or severe.

The causes of upper respiratory infections in cats can be viral or bacterial. Viral infections are more common than bacterial infections and can be caused by feline herpesvirus (FHV-1) or feline calicivirus (FCV). Bacterial infections are usually secondary to viral infections.

Risk factors for upper respiratory infections in cats include stress from overcrowding or poor living conditions. Kittens and older cats are also at a higher risk due to their weaker immune systems.

Upper respiratory infections in cats are highly contagious and can spread easily through direct contact with infected animals or contaminated objects such as food bowls or litter boxes.

The severity of upper respiratory infections in cats can vary from mild to life-threatening. Severe cases may require hospitalization and supportive care, such as intravenous fluids and oxygen therapy.

Prevention is key. Vaccinations against FHV-1 and FCV can help prevent these viral infections. Keeping your cat’s environment clean and stress-free can also reduce the risk of infection.

Treatment for upper respiratory infections in cats includes supportive care such as antibiotics for secondary bacterial infection, antiviral medication for viral infection, fluid therapy to prevent dehydration, and nutritional support to maintain weight.

In conclusion, understanding the symptoms, causes, risk factors, contagiousness, severity prevention methods, and treatment options for upper respiratory infections in cats is crucial for pet owners. By taking preventative measures such as vaccinations and maintaining a clean environment, pet owners can help reduce the risk of infection. If your cat shows any signs of upper respiratory infection, seek veterinary care immediately.


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