Inclusions in equine cytologic specimens.

Inclusions and cellular changes were seen in cytologic specimens from 1 healthy horse, 6 horses hospitalized because of respiratory problems, and 1 horse hospitalized because of colic and hepatitis. Two bronchial aspirates contained detached ciliated cytoplasmic tufts and cytoplasmic inclusions characteristic of the specific degenerative process called ciliocytophthoria. These changes and inclusions resembled those seen in bronchial aspirates from human beings with parainfluenza virus infection. Four bronchial aspirates and 2 serous fluid specimens had nuclear inclusions resembling those seen in a variety of specimens from human beings with herpetic infections. The abnormalities and inclusions were similar to changes seen in cell monolayer and suspension cultures infected with equine herpesvirus type 1.