Feline Upper Respiratory Tract Pathogens: Herpesvirus-1 and Calicivirus

Feline herpesvirus-1 and feline calicivirus are common causes of feline upper respiratory tract disease and can cause clinically indistinguishable syndromes. However, they differ in their physical properties, epidemiology, and spectrum of clinical signs; and the differences can affect the diagnosis, prognosis, and management of these infections. The availability and sensitivity of diagnostic tests also differ for each virus. Diagnosis of both infections can be difficult and is best achieved by combining patient history, physical examination, and microbiologic assay results. Treatment is primarily symptomatic. Vaccination does not prevent infection but can help minimize the severity of clinical signs and duration of shedding.