Use of the lysozyme test in the diagnosis of kerato-conjuctivitis sicca in dogs and cats.

Comparative studies of the lysozyme test (LT) and the Schirmer tear test (STT) revealed that the LT was not reliable in the diagnosis of kerato-conjunctivitis sicca (KCS) in dogs and cats. This is in contrast to its successful use in human patients. No M. lysodeikticus lysating substrates were detectable in the tear fluid of the normal cat.