Feline upper respiratory infection (URI) is perhaps the most frustrating illness facing shelter veterinarians, managers and staff. Many cats enter shelters already silently carrying the viruses that lead to illness; vaccines are partially effective at best; and specific treatments are limited.

Canine respiratory disease complex arises out of an interaction between an assortment of viral and bacterial pathogens; the animal's immune response; and a host of environmental factors. No single strategy will be sufficient for prevention, treatment or control. The good news is we do have many options to reduce the level of environmental contamination and support animals' ability to ward off infection.