Upper respiratory infections are the most common disease challenge in animal shelters, causing significant suffering in cats and kittens and representing a major barrier to shelter cat welfare improvement.
Shelter cats with URI experience the discomfort of respiratory illness compounded by the stress of shelter confinement. The sneezing, eye discharge, and nasal congestion cause significant distress, and the oral ulcers from calicivirus make eating painful. Kittens with severe URI may stop eating, require tube feeding, and develop pneumonia requiring intensive care. The shelter environment itself is a major driver of URI - the stress of unfamiliar surroundings, noise, and loss of control suppresses immunity and reactivates latent herpesvirus. The welfare burden falls most heavily on the most vulnerable animals: neonatal kittens and immunocompromised cats who cannot mount effective immune responses.