Upper respiratory infections, or kitty colds, are prevalent among cats. The most common causes are viruses, including the viruses that constitute the annual booster vaccines. Feline rhinotracheitis virus, feline herpes and feline calicivirus are three viruses that have effects that are diminished, but not prevented, by vaccination.
Acute viral infections may produce fever, congested nasal passages, thick nasal discharge, lethargy and anorexia. Often, a secondary bacterial infection will complicate the primary viral infection. Antibiotics, which are used to treat URIs in cats, will work only if a bacterial infection is present. Unfortunately, drugs that effectively kill these viruses do not exist, and veterinarians are only able to treat the symptoms.
URIs can run a course of seven to 21 days. If your cat is exhibiting symptoms of a upper respiratory infection, take it to your veterinarian.