Abstract

Reproductive management in zoos often requires contraception or physical separation of sexes to ensure long term viability in captive populations.⁴ Correlation between reproductive life histories and uterine pathology has been documented in zoo ungulates, including elephants and rhinoceroces.^1-4 Information on the effects of parity, age, and contraceptive use on lifetime reproductive health in captive pig (Suidae) and peccary (Tayassuidae) species is sparse. This study systematically evaluated the reproductive tract tissues and comprehensive reproductive histories from female babirusa (Babyrousa babyrussa, n=6), red river hog (Potamochoerus porcus, n=10), Chacoan peccary (Catagonus wagneri, n=5), Visayan warty pig (Sus cebifrons, n=5), and common warthog (Phacochoerus africanus, n=26). Age, parity, time-since-last-parturition (parturition gap), contraception exposure, lesion prevalence, and endometrial lesion grade were recorded. Reported contraceptives included PZP, progestins and deslorelin. Red river hogs were most commonly contracepted (42.9%). Babirusa had the highest prevalence of follicular cysts (66.7%), endometrial atrophy (33.3%), endometrial hyperplasia (66.7%), pyometra (66.7%), and uterine neoplasia (66.7%, leiomyoma only). Red river hogs had the highest prevalence of adenomyosis (30.0%). Warthogs had the highest metritis (41.1%) and the second highest uterine neoplasia (23.5%, leiomyoma and vaginal leiomyoma) prevalence. Overall, age was positively correlated with pyometra occurrence (p=0.0167). Contraceptive use positively correlated with adenomyosis prevalence (p=0.05), and parturition gap length positively correlated with metritis prevalence (p=0.033). Babirusa appear to be at highest risk for reproductive tract lesions. These data suggest that risk factors for reproductive tract lesions in Suidae include advanced age, prolonged gaps between pregnancies, and contraception.

Acknowledgments

The authors would like to thank the AAZV Wild Animal Health Fund for funding for this study. The authors would also like to thank all zoos that contributed tissues to this study thus far. The authors would like to extend special thanks to San Diego Zoo and Northwest ZooPath for allowing access to their tissue blocks and slides.

Literature Cited

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2.  Asa CS, Bauman, KL, Devery S, Zordan M, Camilo, GR, Boutelle S, Moresco A. Factors associated with uterine endometrial hyperplasia and pyometra in wild canids: implications for fertility. Zoo Biol. 2014;33(1):8–19.

3.  Hermes R, Hildebrandt TB, Walzer C, Göritz F, Patton ML, Silinski S, Schwarzenberger F. The effect of long non-reproductive periods on the genital health in captive female white rhinoceroses (Ceratotherium simum simum, Cs cottoni). Theriogenology. 2006;65(8):1492–1515.

4.  Penfold LM, Powell D, Traylor-Holzer K, Asa CS. “Use it or lose it”: characterization, implications, and mitigation of female infertility in captive wildlife. Zoo Biol. 2014;33(1):20–28.