Feline upper respiratory infection (URI) is the most common disease in shelter cats, with a complex of viruses and bacteria causing significant individual suffering and population-level management challenges.
URI in shelters creates compounding welfare problems. Affected cats experience respiratory discomfort, oral pain from ulcers, anorexia, and the misery of acute illness in an already stressful environment. The shelter environment - unfamiliar, noisy, filled with strange cat odors - elevates stress hormones that directly suppress the immune responses needed to fight the infection. Cats that came into the shelter healthy can develop URI within days simply from stress. For kittens, URI can rapidly progress to pneumonia and death. The welfare dimension of shelter URI is inseparable from shelter management: better stress reduction through smaller group sizes, hiding spaces, and quiet areas reduces URI rates and improves welfare simultaneously.