Diagnosis and investigation of infertility causes in two female giant pandas using multimodal techniques: a case report

Background: The advancement of artificial insemination techniques for giant pandas has significantly enhanced their breeding success. However, some pandas continue to experience difficulties in conceiving naturally, necessitating a thorough investigation into the underlying causes of infertility. This study aimed to perform pre-pregnancy examinations and diagnose infertility causes on giant pandas with infertility. Methods: A range of diagnostic methods, including behavioral observation, hormone assays, ultrasound imaging, laparoscopy, hysteroscopy, and colposcopy, were employed to conduct pre-pregnancy assessments and diagnose infertility in two giant pandas, designated as #A and #B. Results: Both pandas exhibited normal estrus behaviors, and their progesterone (P4) and estrone (E1G) levels during estrus paralleled those typically seen in successfully breeding individuals during estrus, remaining within the expected physiological range. Ultrasound evaluation of panda #A revealed a fluid accumulation surrounding the ovaries, with echogenicity noted along the walls of the adjacent fallopian tubes, suggesting the presence of hydrosalpinx, which was subsequently confirmed via laparoscopy. Hysteroscopic examination indicated that the vaginal and uterine structures of both pandas were normal. Conclusion: The estrous behaviors and hormonal profiles of the two infertile giant pandas were observed to be within normal ranges. The infertility in one of the subjects was attributed to the presence of hydrosalpinx.