A Tubal Pregnancy in a Rhesus Monkey (Mucacu rnuluttu)

Tubal pregnancy was diagnosed on histological section of a nodule within the uterine tube of a multiparous rhesus monkey. Clinical signs were anorexia and weight loss. The tube contained a placenta of approximately 35 days gestation, but no recognizable embryo or amnion. The ipsilateral ovary contained a degenerating corpus luteum. Tubal pregnancy is the most common type of ectopic pregnancy in women, occurring in approximately 0.3% to 1.0% of pregnancies in the United States ( 121. In animals, all ectopic pregnancies are rare, and tubal pregnancies exceptionally so. A detailed gross description of a third trimester abdominal pregnancy in a hamadryas baboon with apparent tubal placentation was given (13). A literature review from 1680 to date revealed several uteroabdominal pregnancies reported in domestic and laboratory animals, but no tubal pregnancies (4). A multiple abdominal pregnancy in a rabbit was described it was postulated that tubal implantation had initially occurred, even though no embryonic, fetal or placental tissue was present within the tubes at dissection. One tubal and two extrauterine pregnancies in monkeys were reported briefly ( 101. In addition, two abdominal pregnancies were reported in rhesus monkeys ( 1 I), and one tubal pregnancy was reported in a mouse (9). The present case is the only ectopic pregnancy observed at the California Primate Research Center since its establishment in 1962.