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Canine Vaginal Cytology During the

KLAAS POST

Department of Veterinarv Internal Medicine, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7A O WO

SuMMar v Vaginal Smnear Collection although a large intermediate cell may Changes which occur in vaginal Smears were collected from the ves- have a polygonal shape (1). cytology of the bitch during proestrus, tibule using a microscope slide. The Parabasal cells have a large vesicu- estrus, metestrus and anestrus are labia of the vulv a were massaged lar nucleus and the cytoplasm stains correlated. The terms superficial cell externally and then separated using somewhat darker than the interme- index and karvopyknotic index are the thumb and index finger (Figure 1). diate and superficial cell cytoplasm introduced and explained in order that The microscope slide was gentlN (Figure 6). they may be used to describe vaginal pressed to the surface of the vestibular Other cells recognized were foam cytological changes and to assist in mucosa. The smear was made by lay- cells, metestral cells, erythrocytes, breeding programs. ing the slide on another slide and pul- , as well as mucus and ling it over the surface of the second debris. In?tr'odIUCtiOn7 slide (Figure 2), which was then air The investigation of the exfoliated dried and stained. Smears were Patterns of' Vaginal Stmiears During cells in the canine vaginal smear has obtained every Monday, Wednesday CYclic Change been studied previously (1,2,3A4,5,6), and Friday during proestrus, estrus Under influence, during but most wvorkers have used special and metestrus. The smears were proestrus and early estrus, the cells of stains that are not always readily stained using a Wright's Giemsa stain the vaginal begin to prolif- available to the practitioner or are very (Hema Tek, Slide stainer. Ames. Elk- erate, differentiate, and exfoliate (1 .6). time consuming and difficult to use. A hart, Indiana). As a result, the number of cell layers hematological stain, Wright's Giemsa, increase and the predominant cell type although not a new technique, is the El aluation of Vaginal Smnear.s on the surface changes rapidly from only stain presently being used by cli- The different cell types are illus- basal and parabasal to intermediate, nicians and students at the Veterinary trated (Figure 3). The exfoliated and then to a superficial cell type. It is Teaching Hospital at the Western Col- epithelial cells were classified as super- now possible to compile a superficial lege of Veterinary Medicine. There- ficial, intermediate and para basal cells cell index (SCI) and a karvopyknotic fore, Wright's Giemsa was used in this ( 1). The superficial epithelial cells are cell index (KPI). A total number of study in the anticipation that this stain polygonal in shape (Figure 4). The 100 or 200 cells are counted. canl be used to obtain sufficient infor- superficial epithelial cells were further As proestrus progresses the SCI will mation. Similar types of hematologi- classified as anuclear (squame), rapidly approach 100% and remains cal stain used in practice should work pvknotic and nucleated cells. high throughout estrus. The KPI equally \well on vaginal smears. The intermediate cells were divided increases slowly and reaches 80% by in large and small intermediate cells, estrus and then increases near 100% at Malaterial.s aId Methodls both showing xesicular nuclei (Figui-e ovulation. Both the SCI and KPI will An7im17als Adult bitches which 5). The shape is mostly rounded fall sharply after ovulation at the onset were previously bred and had shown normal estrous cycles were studied. Number of from SC1 = cells superficial epithelial layers x 100 The described in this vaginal cytology Total number of epithelial cells report is from a single female over a complete cycle and represent expected = Number of anuclear cells or cells with pyknotic nuclei x 100 ) cell chaniges that occur in the vaginal KPI smear. Total number of superficial cells

Can Vet J 1985; 26: 101-104. 101 5t 6

FIGURE 1. Collection of specimen showing the microscope slide ~ i-,~ ~ ~ gently pressed to the surface of the vestibular mucosa. FIGURE 2. The collection slide (top) is pulled over the surface of the second slide (bottom). The latter is air dried and ready for staining. 9w FIGURE 3. Epithelial cells; nuclear (a), anuclear (b), interme- diate (c), parabasal (d), foam cell (e), (f) and mucus ~~~~~~~~~~~101(g). X400. FIGURE 4. Large anuclear supe cial cell or squame. X 1000. AW. FIGURE 5. Two intermediate cells. X 1000. FIGURE 6. A parabasal cell. Xo100. 13 ~~~~~~~~~~~~~~~~~~~FIGURE7. Anestrus (see text for description). XlOO0.

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FIGURE 8. Early proestrus (see text for description). X400. FIGURE 9. Late proestrus (see text for description). X400. FIGURE 10. Estrus (see text for description). XIOO0. FIGURE 11. Estrus showing red blood cells. X400. FIGURE 12. Metestrus (see text for description). X400. FIGURE 13. Smear taken from anterior using speculum and moistened Q-tip. Cell type present is anuclear superficial cells. X100. FIUURE 14. Smear taken from vestibule using the method de- scribed in this paper. Cell types present are anuclear and few pyknotic superficial cells. X100. 141

103 of metestrus. The beginning of metes- metestrus cells. Foam cells, parabasal determined and ovulation can be trus can also be determined by the sub- cells that contain cytoplasmic vacules, determined in retrospect by a precipit- tle appearance of neutrophils, para- may also be seen during this phase of ous drop in indices. Similarly, anovu- basal and small intermediate cells in the cylce (Figure 12). lation, split estrus, false estrus and the vaginal smear. source of vaginal bleeding can be Anestrus - Very few cells are usu- Discussion determined. Inflammatory conditions ally encountered during this phase. In the author's opinion, there is no of the reproductive tract can be inves- The cells present are usually of the entity in the clinical evaluation of the tigated by vaginal cytology and tum- intermediate and parabasal type with a reproductive cycle as important as ors such as lymphosarcoma and moderate number of neutrophils pres- vaginal cytology. Many infertility transmissible veneral tumor can be ent or absent (Figure 7). problems can be corrected by simply investigated and differentiated from Proestrus and Estrus - During interpreting vaginal cytology. The conditions such as vaginal hyperplasia early proestrus the cells become more breeding cycle of each bitch may vary (8). Interpretation of vaginal cytology differentiated and all cell types and many breeders and veterinarians is absolutely necessary to determine encountered are superficial, interme- may be misled by these variations. the optimum time for artificial insemi- diate and parabasal epithelial cells. It has been recommended for cyto- nation, when to send a bitch to a stud, Erythrocytes are also present (Figure logical examination, that cells be and when the fertile period is over. 8), and neutrophils may be seen during obtained from the vagina rather than the first few days. By midproestrus the the vulva (7). However, others feel that Acknowledgments neutrophils are absent as are the para- it is unnecessary to collect material I would like to thank Dr. Reuben basal and intermediate cells. In late from the anterior vagina in the bitch Mapletoft, Department of Herd Med- proestrus (Figure 9) virtually only (1). Our findings (Figures 13 and 14) icine and Theriogenology, Western superficial cells are present in the agree with the latter approach and for College ofVeterinary Medicine for the smear although red blood cells may practical purposes it is sufficient to use use of Figure 2 and his valuable con- still be seen. Late proestrus and early the vulvar labia to collect cells that structive criticism of the paper. estrus are difficult to distinguish with have been exfoliated further anterior, vaginal smears. The vaginal smears especially during proestrus and estrus. during late proestrus and early estrus It also prevents the introduction of References become clear due to a disappearance contaminating material from the pos- 1. SCHUTTE AP. Canine vaginal cytology. J of debris with only pyknotic and anu- terior vagina to the anterior vagina. If Small Anim Pract 1967; 8: 301-317. clear superficial cells being present. one deals with a nervous bitch it is 2. PHEM ISTER RD, HOLST PA,SPANOJS. HOPWOOD ML. Time of ovulation in the beagle bitch. Mid estrus is characterized by the quite difficult to pass a vaginal specu- Biol Reprod 1973; 8: 74-82. presence of superficial cells, most of lum and to take a smear from the ante- 3. BELL ET, BAILEY JB, CHRISTIE DW. Studies on which are anuclear (Figure 10) and the rior vagina. vaginal cytology during the canine oestrus background of the smear is clean and The vaginal mucosa must not be cycle. Res Vet Sci 1973; 14: 173-179. clear. Erythrocytes may or may not be scraped as one is only interested in 4. HOLST PA, PHEMISTER RD. Onset of diestrus in present during estrus (Figure 11). exfoliate cytology. Similarly, smears the beagle bitch: definition and significance. Metestrus - There are numerous must not be taken from an area that is Am J Vet Res 1974; 35: 401-406. cells which are of the intermediate and too close to the mucocutaneous junc- 5. ROSZELJF. Genital cytology of the bitch. Vet parabasal variety. A few superficial tion as debris and cutaneous (keratin- Scope XIX 1975; 3-15. cells may be seen during metestrus. A ized) cells will be picked up from this 6. CONCANNON PW. Reproductive physiology characteristic is the very and endocrine patterns of the bitch. In: Kirk phenomenon area. RW, ed. Current veterinary therapy VIII. high number of neutrophils in this Using vaginal cytology many prac- Philadelphia: WB Saunders, 1983: 886-901. phase which reappear as soon as tical applications can be applied to the 7. SENIOR, DF. Infertility in the cycling bitch. metestrus starts. If parabasal or inter- evaluation of both the normal and Compend Contin Educ 1979; 1: 17-23. mediate cells are infiltrated by white abnormal bitch. For example, the 8. PERMAN V. ALSAKER RD, RILLS RC. Cytology of blood cells they are referred to as optimum time for breeding can be the dogand cat. Am Anim Hosp Assoc 1979.

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