Date of Award

12-1-1975

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Biology

Abstract

More than 1500 vaginal smears and 75 0 urine samples were collected from 18 captive mountain lions, Felis concolor Linnaeus, 17 bobcats, Lynx rufus (Schreber), and 9 Canadian lynx, Lynx canadensis Kerr, from 1973-1974. Four types of epithelial cells were observed in the vaginal smears: parabasal, intermediate, cuboidal superficial and nivi- cuiar superficial. The smears were classified as anestrus , proestrus , estrus or metestrus on the basis of the four cell types and other smear characteristics . The reproductive behavior in captive mountain lions, bobcats, and lynx was also analyzed and the relationship between vagi- nal smear types and reproductive behavior patterns was determined.

The reproductive behavior patterns of the three species were similar to each other and to patterns in the domestic cat, Felis catus Linnaeus , and included stages of anestrus, proestrus, estrus and metestrus. There was a highly significant association (P^. 0.001) between behavioral patterns and cytological appearance of the vaginal smear at every stage of the estrus cycle for each species.

The change in type of vaginal smear, total urinary estrogen excretion and overt behavior were used to monitor seasonal variation in the reproductive cycle of two mountain lions and three bobcats from January 5, 1973 to December 31, 1974 . One mountain lion had seven the other s ix estrus periods over the two years . These e^rus periods occurred in seven separate months from March through November. However, eight (61%) of the estrus periods occurred from March through June indicating a seasonal influence on reproduction. The estrus periods averaged 8.1 days in length. Total estrogen excretion during the estrus perio- s averaged 49.82 xg/12 hr urine sample. The estrus cycle averaged 37.6 days and the estrous cycle averaged 5 9.5 days in length.

Bobcats were observed to be seasonally polyestrus . Over a scan of two years, each of the three bobcats had five estrus periods from late March through early August. The estrus periods averaged 7.6 days in length. Total estrogen excretion during the estrus periods averaged 21.41 jjg/12 hr urine sample. The estrus cycle averaged 37.3 days in 1. * • » :’j§? ' • ' length and the estrous cycle averaged 46.4 days.

Mountain lions, bobcats and lynx were injected daily with varying amounts of estradiol benzoate (EB) or pregnant mares serum gonadotrophin (PMSG) for up to 15 days to determine the utility of these hormones in inducing estrus and physiological levels of total estrogen excretion. The change in vaginal smear type and total estrogen excretion over the course of gestation also was determined in three mountain lions.

Daily injections of 75-90 jjg EB or 80-125 IU PMSG for 15 days were effective in inducing estrus and physiological levels of total estrogen excretion in mountain lions. Daily injections of 20-30 jup EB or 70- 90 IU PMSG for 15 days were effective in bobcats. Daily injections of 20 i^g EB or 60-100 IU PMSG for 15 days were effective in lynx. The number of copulations and amount of total estrogen excretion appeared to be important in determining whether bleedings resulted in pregnancy.

The vaginal smears of the three pregnant mountain lions contained predominantly parabasal cells from the second through the thirteenth week of gestation, except for one week when superficial cells were predominant. Total estrogen excretion was less than 11.0 mg/12 hr urine sample during the first week of gestation and gradually increased to an average of 44.28 mg/12 hr urine during the thirteenth week of gestation. There were minor peaks in total estrogen excretion during the same weeks that superficial cells were predominant. The vaginal smear was not useful in diagnosing pregnancy in the mountain lions.

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