Differences in Mare and Foal Oral Smears

Abstract

Roszel (1975) recently reviewed the literature on vaginal exfoliative cytology and cell nomenclature as it relates to cytohormonal patterns and genital cancer in the dog. Her findings on cellular changes during the estrous cycle in dogs were in general agreement with those of Christie and Bell (1973) and she reaffirmed the value of cytological evaluation for determination of optimal breeding time. Although she described differential cell count methods, based upon different morphological expressions of vaginal cell maturation used in human studies (Karyopycnotic Index, Maturation Index, Maturation Value, and others), she did not use these methods to report her data on dogs. The nomenclature advocated to describe exfoliated vaginal cells from dogs was like that used for exfoliated human vaginal cells observed in smears: i.e. basal, parabasal, intermediate and superficial. She described additional cell types observed in vaginal smears from dogs and suggested that further study of the various indices using differential cell counts were in order. Mowrer et al. (1975) reported studies of vaginal cytology to improve cat breeding but did not use maturation indices to classify their observations. Bach (1973) described the use of exfoliative cytology of peritoneal fluid in the horse but did not use maturation indices to present his data. We are not aware of any oral or vaginal exfoliative cytology studies for horses. Sequential steps in the development of human buccal cells, especially with respect to the degeneration of the nucleus, have recently been described , Lee et al. 1973 The inferred sequence of degeneration of intermediate cells, based on the decrease in nuclear size and dry mass, was as follows: cells with round nuclei degenerated to form cells with oval nuclei; cells with oval nuclei degenerated to form cells with rod-pycnotic nuclei; and, rod-pycnotic nuclei became smaller, resulting in cells with pycnotic nuclei. Finally, complete nuclear degeneration resulted in anucleate cells.Using epifluorescence ultra-violet phase contrast microscopy with oral smears from humans, an additional cell type was observed and called "ghost" (Pappelis, et al. 1976). Although often observed in smears, the location of ghost cells in