A diagnosis of viral respiratory infection typically is based on the history and physical exam of the kitten or cat. Specific tests to ascertain the specific causative virus are not performed routinely unless there is a disease outbreak in a large group of cats housed together.
If the cat is affected severely, the examining veterinarian may elect to perform blood tests. Serology tests for feline leukemia virus, or FeLV, and feline immunodeficiency virus, or FIV, should be performed in cats with recurrent episodes of disease. Cats that fail to improve after two weeks, and vaccinated adult cats that have severe respiratory symptoms, also should be evaluated for FeLV and FIV.
In order to establish a definitive diagnosis, on infrequent occasions the veterinarian may perform other tests, such as viral inclusion body tests of conjunctival biopsies or scrapings, and direct immunofluorescence of nasal swabs for virus-infected cells. Virus isolation from cell cultures can be achieved by taking swabs of the affected areas, and serology can evaluate rising antibody titers.
