Upper respiratory tract infections (cat flu) are extremely common in cats, particularly in rescue and multi-cat environments, causing significant welfare impact.
Cat flu causes acute suffering through nasal congestion that prevents cats from smelling food, oral ulcers that make eating painful, and conjunctivitis that impairs vision. Severely affected cats stop eating and drinking, requiring supportive care including fluid supplementation and assisted feeding. Herpesvirus corneal ulceration can cause permanent corneal scarring and vision impairment. Calicivirus causes virulent systemic disease (VS-FCV) with high mortality in some strains. Shelter environments provide ideal conditions for disease spread requiring robust vaccination, isolation, and hygiene protocols. Stress management in shelter environments is critical as stress triggers herpesvirus reactivation. Reducing shelter stay duration through adoption programs reduces cumulative welfare burden.