New technologies for the study of carnivore reproduction
Publication Type: |
Journal Article |
Year of Publication: |
2006 |
Authors: |
Barbara S. Durrant, Nicole Ravida, Thomas Spady, Alice Cheng |
Publication/Journal: |
Theriogenology |
Keywords: |
carnivore, infrared thermography, lh, ursid, vaginal cytology |
ISBN: |
0093691X |
Abstract:
Routine analysis of urinary metabolites of estrogen and progesterone provided substantial information about the estrous cycle of
bears. However, these data alone were not adequate to determine the precise timing of ovulation needed to maximize AI success
rates, or to distinguish between pregnancy and pseudopregnancy. Therefore, there is a critical need to develop technologies that will
enhance understanding of the reproductive mechanisms of ursids. Using the domestic dog as a model, three techniques were
investigated for potential application to the propagation of captive endangered bears. In a modification of standard staining of bitch
vaginal cells, trichrome staining of giant panda cells revealed two consistent chromic shifts 9 and 2 days prior to the periovulatory
decrease in urinary estrone sulfate, enhancing the ability to predict ovarian events preceding ovulation. To further define the
relationship between the decrease in estrogen and ovulation, the utility of a rapid immunochromatographic LH assay was
investigated for giant pandas using a commercial LH kit canine serum. Serum collected during estrus exhibited positive test results,
indicating the cross-reactivity of giant panda LH with canine LH antibodies, and preliminary data supported further development of
the LH kit for the detection of LH in bear urine. Due to the limitations of hormone analysis for distinguishing pregnancy from
pseudopregnancy in canids and ursids, forward-looking infrared thermography was evaluated as a method to visualize proliferating
placental tissue, fetuses, or both. While further investigation is needed to confirm the utility of thermal imaging for pregnancy
diagnosis in the domestic bitch, pregnancy and pseudopregnancy were successfully detected in two giant pandas.