Feline upper respiratory infection (URI) is perhaps the most frustrating illness facing shelter veterinarians, managers and staff. Many cats are chronically infected, vaccines are partially effective at best, and specific treatments are limited. URI is very easily spread by fomites or droplet transmission, and some URI agents are resistant to disinfection.
There are several factors that contribute to URI including overcrowding, stress on the cat, the cleanliness of the environment, the air flow and low quality food. Many of these factors, and they are not a full list, make it nearly impossible to eradicate URI in an environment.
The two biggest contributors are overcrowding and stress. This can cause severe breakouts in the population. Sadly overcrowding is a typical issue in a shelter environment due to the amount of people who are turning in pets, the small areas they have to live in and the ideal that the US should work towards becoming a no kill nation.
Tragically, such efforts may not only fail to improve the number of animals adopted, they may actually lead to increased disease and death. Even in a boarding facility or vet clinic, it is important to anticipate times of peak population, recognize that these will be periods of increased risk for respiratory disease outbreaks, and plan sufficient additional staff that husbandry is not compromised.
There are some very clear signs to be on the lookout for in cats. As soon as you suspect a URI the cat should be removed from the situation and isolated as best as possible. Then you will need to keep an eye on the rest of the cat population as most URIs are caught by other cats quickly. Observe your cats for the following:
A drippy nose that has clear or color discharge
Coughing or sneezing
Eyes that are swollen or red
Ulcers in the mouth, on the gums or even on lips
Loss of incentive, fever, or no interest in food