Upper Respiratory Infection in Cats

Upper respiratory infections are common illnesses,
especially in kittens and young cats.

Feline upper respiratory infections are one of the most common respiratory diseases I see in my veterinary practice, especially when kittens and young cats are involved. Though upper respiratory infections can affect cats of any age, young cats are more prone to the disease than older cats.

Respiratory infections are especially common in kittens and cats recently adopted from a kennel or cattery situation, such as a shelter, pound, pet store or other pet care facility where large numbers of cats are housed in a relatively small area. This is a result of the extremely contagious nature of the disease.

Feline Upper Respiratory Infections

The majority of upper respiratory infections in cats (approximately 90%) are caused by two common viruses:

• feline calicivirus
• feline herpesvirus (also known as feline rhinotracheitis)

Other less common causes of feline respiratory infections include:

• Chlamydophila, formerly known as Chlamydia
• Mycoplasma
• Bordetella
• other viral and bacterial infections

Symptoms of Upper Respiratory Infection in Cats

Symptoms frequently seen in cats with upper respiratory infections include:

• sneezing
• coughing
• runny eyes
• runny nose
• wheezing
• fever
• ulcers (sores) on the mouth and tongue
• harsh voice

Though may cats with upper respiratory infections suffer only mild symptoms and recover without medical intervention, the potential for complications does exist. Pneumonia can occur as secondary bacterial invaders affect the lungs of an infected cat and symptoms of pneumonia can become quite serious. In addition, some cats with upper respiratory infections may experience a fever high enough to cause a lack of appetite and cause dehydration. Also, cats experiencing ulcers in the mouth or on the tongue may become painful enough to avoid eating. These cats may require medical intervention and nursing care to aid recovery.

Spread of Upper Respiratory Infections Between Cats

Most upper respiratory infections are spread through aerosolization which occurs when an infected cat sneezes, much like when a person has a cold. Upper respiratory infections are extremely contagious and easily passed from one cat to another. Fortunately, in most cases, people do not become infected.

Cats infected with the feline calicivirus and feline herpesvirus may remain infected with the viruses for life and can also act as carriers of the diseases. Cats infected with the feline herpesvirus especially are prone to recurrence of symptoms under periods of stress.

Vaccination Against Feline Upper Respiratory Disease

Vaccination against feline calicivirus and feline herpesvirus (feline rhinotracheitis) are available and are considered core vaccines, meaning that these vaccines are considered to be important for all cats. Vaccination can be started for kittens as young as 6-8 weeks of age and should be administered in a series initially, usually given 3-4 weeks apart. The vaccine should be boostered in one year and repeated every one to three years for adult cats. Your veterinarian can help you determine an appropriate vaccination schedule for your cat.

Vaccinations also exist for Bordetella and for Chlamydophila in cats. However, these vaccines are not considered to be core vaccines and are generally not recommended for most cats.