Retrospective characterization of reproductive tract lesions in relation to age, parity, and contraception in captive suidae and tayassuidae

Reproductive management in zoos requires contraception or physical separation of sexes to ensure captive population viability, but information is sparse on the effects of parity, age, and contraceptive use on lifetime reproductive health in captive Suidae and Tayassuidae species. This retrospective study evaluated reproductive tissues and histories from babirusa (Babyrousa babyrussa), red river hog (Potamochoerus porcus), Visayan warty pig (Sus cebifrons), common warthog (Phacochoerus africanus), Vietnamese pot-bellied pig (Sus scrofa domesticus), domestic cross pig (Sus scrofa), Sunda island pig (Sus celebensis timoriensis), Eurasian boar (Sus scrofa), Bornean bearded pig (Sus barbatus), Ossabaw island hog (Sus scrofa domesticus), Guinea hog (Sus scrofa domesticus), Chacoan peccary (Catagonus wagneri), and collared peccary (Pecari tajacu). Age, parity, litter size, time-since-last-parturition, contraception exposure and type, and lesion prevalence were recorded. Reported chemical contraceptives used in females included porcine zona pellucida vaccine, progestins, GnRH analogues (deslorelin and leuprolide). Average litter size was significantly different between species (p < 0.0001) with the common warthog having the largest average litter size (3.5 ± 0.2 offspring/litter). There was a trend for age to be positively correlated with leiomyoma/sarcomas (r = 0.6135; p = 0.0789). Progestins (medroxyprogesterone acetate, megestrol acetate, depomedroxyprogesterone acetate) were positively correlated (r = 0.8946; p = 0.0161) and GnRH analogues (deslorelin, leuprolide; subcutaneous) were negatively correlated with ovarian cysts (r = 0.9743; p = 0.0010). Across all species, there was a trend for age to be negatively correlated with folliculogenesis (r = −0.6528; p = 0.0566) and parturition gap length to be negatively correlated with follicular cysts (r = −0.8944; p = 0.1). Common warthog, babirusa, and Vietnamese pot-bellied pigs had the greatest diversity of uterine lesions and the highest prevalence of reproductive tract lesions of all species evaluated. Four of the 27 males (14.5%) in the dataset had testicular tumors. All males had prominent testicular interstitial cell populations, which appears to be within normal limits for these species. These data suggest prolonged gaps between pregnancies, age, and contraception are risk factors for reproductive tract lesions in Suidae.