In cats, URIs are usually caused by feline herpesvirus or calicivirus and spread rapidly in shelters and multi-cat homes. Signs include sneezing, watery or purulent nasal and eye discharge, fever, and reduced appetite. Most healthy adult cats recover with supportive care, but kittens and immunocompromised cats may develop pneumonia. Birds with URIs may show tail bobbing, open-mouth breathing, and nasal discharge, often indicating bacterial or fungal infections requiring prompt veterinary attention. Reptiles with URIs produce mucus bubbles from the nostrils, frequently linked to inadequate temperatures or humidity. Treatment varies by species but may include antibiotics, antiviral support, nebulization, and husbandry corrections.