Search

Placental changes associated with SCNT have been described in several species, but little information is available in this area in the horse. We evaluated the ultrasonographic, gross, and histopathological characteristics of placentas from three successful and five unsuccessful equine SCNT pregnancies, established using cells from a single donor horse. Starting at approximately 6-month gestation, the pregnancies were monitored periodically using transrectal (TR) and transabdominal (TA) ultrasonography (US) to examine the placentas, fetal fluids, and fetuses. Of the five mares that aborted, one mare did so suddenly without any abnormal signs detected by US and four had enlarged umbilical vessels visible on TA-US before abortion. Placental edema (TR-US) and intravascular thrombi in the umbilical cords were seen (TA-US) in two of these four mares; one mare aborted shortly after acute placental separation was identified on TA-US. In three mares that delivered live foals, TA-US showed engorged allantoic vessels and enlarged umbilical vessels. Two of these mares had placental thickening visible on TR-US, interpreted as a sign of placentitis, that subsided after aggressive medical treatment. Seven of the eight placentas were submitted for gross and histopathological examinations after delivery. All placentas had some degree of edema, abnormally engorged allantoic vessels, and enlarged umbilical vessels. Placentitis, large allantoic vesicles, cystic pouches in the fetal part of the cord, and hemorrhages and thrombi in the umbilical vessels were detected only in placentas from mares that aborted. Equine pregnancies resulting from SCNT may be associated with placental pathologies that can be detected using ultrasonography. However, interpreting their severity is difficult. Although placental abnormalities have been observed in SCNT pregnancies in other species, to the best of our knowledge, placentitis has not been previously reported and may be an important complication of equine SCNT pregnancies, leading to pregnancy loss., (Copyright © 2016 Elsevier Inc. All rights reserved.)

The objective of this study was to determine the pharmacokinetics of CCFA in mares with placentitis and evaluate the disposition of the drug in fetal fluids, fetal membranes, colostrum, and serum of foals. A secondary objective was to obtain pilot data regarding the efficacy of CCFA for improving foal survival in mares with placentitis. Twelve pregnant pony mares were enrolled in the study, inoculated with Streptococcus zooepidemicus, intracervically and assigned to one of three groups: CEFT (n = 3; administered CCFA only; 6.6 mg/kg, i.m., q96h); COMBO (n = 6; administered combination therapy of CCFA, altrenogest, and pentoxifylline); UNTREAT (n = 3, no treatment). Treatment was initiated at the onset of clinical signs. Concentrations of desfuroylceftiofur acetamide (DCA), the acetamide derivative of ceftiofur and desfuroylceftiofur metabolites, were measured using high-performance liquid chromatography. Maximum and minimum serum concentrations of DCA at steady state in treated mares were 2.40±0.40 μg/mL and 1.06±0.29 μg/mL, respectively. Concentration of DCA in colostrum was 1.51±0.60 μg/mL. DCA concentrations in placenta and fetal tissues were very low (median = 0.03 μg/mL) and below the minimum inhibitory concentration of relevant pathogens. DCA was not detected in amniotic fluid or foal serum. Treatment did not appear to improve foal survival (CEFT: 0/3; COMBO: 2/6; UNTREAT: 2/3). Bacteria were recovered from the uterus of most mares postpartum and from blood cultures of most foals regardless of treatment., (© 2012 Blackwell Publishing Ltd.)