Upper Respiratory Infection in Cats

These infections are also referred to as Feline Infectious Respiratory Disease, or Feline Upper Respiratory Disease Complex (URD) in the veterinary community. The infections vary in severity and have the potential to become life threatening.

Upper respiratory infections are extremely common ailments among cats. Most often the presence of an upper respiratory infection is seen by ocular, nasal, throat and lung irritation and discharge. These infections are spread from contact with other infected cats, and are especially rampant in areas where large groups of cats interact with each other. Kittens, unvaccinated cats, elderly cats and cats with immune deficiencies are the most susceptible to upper respiratory infections.

While there are different forms of upper respiratory infections, they share similar symptoms. They are as follows:

• Nasal discharge (can be containing pus or be clear)
• Ocular discharge
• Enlarged lymph nodes
• Coughing
• Sneezing
• Mouth ulcers
• Loss of appetite
• Weight loss
• Conjunctivitis (inflamed eyelids)
• Fever
• Depression
• Discomfort
• Lethargy
• Blepharospasms (squinting)

Your cat may exhibit many or few of these symptoms. Cases change in severity from cat to cat.

Upper respiratory infections are mainly caused by viral infections, however, in rare cases bacterial infections may be responsible. 

Feline Herpesvirus (FHV) 

A more severe form of virus that remains in the cat’s body for the rest of its life. Eye infections are commonly seen with this virus, along with coughing, sneezing, loss of appetite, pharyngitis (sore throat) and inflamed trachea. The virus will manifest itself whenever the cat experiences a time of stress thereafter in its life, with the cat being potentially contagious forever.

Feline Calicivirus (FCV) 

Less severe symptoms are experienced with this virus although more mouth ulceration may be present. There is also an increased risk of developing pneumonia with this virus. The cat may become a carrier once recovered, and could then be contagious whenever shedding the virus.

Bordetella Bronchiseptica 

A bacterial infection that may cause upper respiratory problems in cats. Generally associated with fever, sneezing, swollen lymph nodes and lung complications.

Chlamydophila Felis 

A bacterial infection often associated with eye infections and mild sneezing.

Mycoplasma 

A bacterial infection with symptoms of ocular discharge and eye swelling. 

Feline Reovirus 

A viral infection of the intestines that can sometimes mimic symptoms of a respiratory infection.

Pasteurella 

A bacterial infection that is often transmitted via animal bites. 

All of the aforementioned infections become rampant in situations where many cats are in contact with each other. Because of this, animal shelters, feral cat colonies, and any other large group of cats are at the highest risk of housing viral or bacterial infection epidemics. These upper respiratory infections can be spread from cats hissing, spitting, grooming or even sleeping near each other. Sharing food dishes or litter boxes can also spread infection.

Your vet will likely examine the cat and take note of all specific symptoms your cat is experiencing to rule out other possibilities. The vet will match your cat's symptoms to characteristic clinical signs associated with each type of upper respiratory infection to diagnose the animal. 

At this point, if your vet is still unsure of the type of infection at hand, or if the cat is responding very poorly to the infection, a PCR (Polymerase Chain Reaction) test will be administered. A swab from the mouth, eye or throat is collected and then sent to a lab for the test to be run. 

Further tests may be run if FIV (Feline Immunodeficiency Virus) or FeLV (Feline Leukemia Virus) is suspected. If pneumonia has developed, a transtracheal wash may be done to collect lung samples. If the condition has become chronic, further tests may be needed including blood tests, chest and skull X-rays, and culture tests of abnormal discharge.

There is no cure for viral infections, so treatment is symptomatic. Your vet will combine some or all of these methods depending on the symptoms your cat is experiencing, and the severity of the infection. 

Antibiotics 

If your cat has developed any secondary infections due to the virus, antibiotics will be prescribed to stop the infections from progressing. 

Steam Inhalation 

To restore some function to the nose, and to entice eating through aromas, a cat may be subjected to steam to loosen or liquify nasal discharge.

Injectable Interferons 

If the virus is caught early on, injecting these proteins may help fight the infection before it fully develops in your cat.

Topical Antiviral Agents 

These agents are applied locally as an ointment or cream to treat the infection. Often, trifluridine, idoxuridine or cidofovir will be prescribed.

Ophthalmic Ointment 

This ointment is used to treat eye infections and irritants affecting the cat.   

Appetite Stimulants 

If the cat still refuses to eat after wet food or aromatic food in oil have been given, an appetite stimulant will be given to help prevent the cat from developing anorexia.

Feeding Tube

If weight loss becomes too severe and the cat is not responding to food, a feeding tube may be administered to ensure the cat is receiving nutrients and fluids. 

A virus will usually run its course in 1-4 weeks. If it persists longer, another vet appointment may be necessary. To prevent the infection from spreading to other cats, all items the cat has been in contact with should be sanitized. Bleach, accelerated hydrogen peroxide, or trifectant (potassium peroxymonosulfate) are excellent agents for killing the viral or bacterial remains. Fresh air should be ventilated into the area to remove any infected aerosol content. Keep the cat quarantined for some weeks after symptoms have disappeared, and vaccinate any other cats in the home in the meantime. 

Reduce any possible stress your cat may experience. Especially with FHV, cats are prone to flare ups whenever experiencing stress. Diet change may be needed in cases of symptom recurrence, along with additional veterinary oversight to ensure FIV or FeLV have not developed.