A cat's upper respiratory infection (URI) is akin to a common cold in humans but is specific to felines. Viruses like feline herpesvirus and calicivirus or bacteria such as Chlamydophila felis typically cause these infections. Typical symptoms may involve sneezing, nasal congestion, conjunctivitis, and discharge from the nose or eyes. Additional signs can include fever, lethargy, or a decrease in appetite in some cats.