A 5-year-old female fennec fox weighing 1 kg presented to the Veterinary Medical Center, Chungbuk National University with swelling of the mammary glands and hematuria. There were no significant complete blood count (CBC) or serum chemistry findings. The uterus obtained by ovariohysterectomy was filled with blood-clot-like material. The uterine fluid contained erythrocytes, a few leukocytes, and bilirubin crystals without bacteria. The progesterone concentration in the blood serum the day before ovariohysterectomy was 7.3 ng/ mL, which is higher than anestrus and lower than a true pregnant condition in a fennec fox. Despite the low blood progesterone concentration and absence of a fetus in the uterus, the histopathological zonary placental findings indicated that the fennec fox had been pregnant. This is the first case report of hematometra associated with fetal death in a captive fennec fox.

This study investigated potential relationship between fetal deaths and plasma progesterone concentrations of bitches. Serial ultrasonographic examinations were performed on small-pet 23 dogs from gestation day (GD) 15 through parturition. The dogs were 3 non-pregnant bitches, 9 spontaneous delivery bitches, 6 partial early embryonic death bitches, 2 whole early embryonic death bitches, and 3 aborted bitches. The late pregnancy (GD 51-54) appeared in 2 of the 3 aborted bitches and the hypoluteoidism appeared in 1 of the 3 aborted bitches. The plasma progesterone concentrations of partial early embryonic death bitches (n=6) showed no significant difference when compared with the spontaneous delivery bitches. We observed that plasma progesterone concentrations were dramatic decrease before the onset of embryonic death in whole early embryonic death bitches that plasma progesterone concentrations of aborted bitches at late pregnancy were significantly decreased when compared with those of spontaneous delivery bitches. The plasma progesterone concentrations of the hypoluteoidism bitch were lower than those of spontaneous delivery bitches. At the hypoluteoidism bitch, fetuses were resorbed in early pregnancy and aborted in late pregnancy. On the basis of the results, the diagnosis of partial early embryonic death could not be confirmed without ultrasonographic examination. The partial early embryonic death was considered a spontaneous phenomenon and uncorrelated with plasma progesterone concentration. However, aborted bitches and whole early embryonic death bitches were related to plasma progesterone concentrations and that of bitches gradually decreased before fetal death. These findings suggest that administration of progesterone may be a useful preventing agent against fetal death.