J Vet Sci.  2007 Sep;8(3):289-293. 10.4142/jvs.2007.8.3.289.

Time of initial detection of fetal and extra-fetal structures by ultrasonographic examination in Miniature Schnauzer bitches

• Kim BS
• Son CH

• KMID: 1090805
• DOI: http://doi.org/10.4142/jvs.2007.8.3.289

Abstract

Serial ultrasonographic examinations were performeddaily on 9 Miniature Schnauzer bitches from the 15th dayof gestation until parturition to determine the time thegestational structures were first detected. The gestationalage was timed from the day of ovulation (day 0), whichwas estimated to occur when the plasma progesteroneconcentration was >4.0ng/ml. The gestational length in 9Miniature Schnauzer bitches was found to be 63.0+/-1.7(range 61-65) days. The initial detection of the fetal andextra-fetal structures were as follows: gestational sac atday 18.0+/-0.9 (17-19); zonary placenta in the uterine wallat day 24.9+/-1.1 (23-26); yolk sac membrane at day 25.0+/-0.9 (24-26); amnionic membrane at day 27.7+/-1.0 (26-29); embryo initial detection at day 22.6+/-0.5 (22-23);heartbeat at day 23.4+/-0.5 (23-24); fetal movement at day32.5+/-0.8 (32-34); stomach at day 31.2+/-1.6 (29-33);urinary bladder at day 32.6+/-1.8 (31-35); skeleton at day34.9+/-1.6 (34-38) and kidney at day 42.2+/-0.7 (41-43).

Keyword

gestational structures; Miniature Schnauzer bitches; ultrasonography

MeSH Terms

Animals
Animals, Newborn
Dogs/*embryology
Female
Fetal Development/*physiology
Fetus
Gestational Age
Litter Size
Pregnancy
Progesterone/blood
Ultrasonography, Prenatal/*veterinary

Figure

• 

  Fig. 1 Ultrasonograms of the extra-fetal structures in pregnant Miniature Schnauzer bitches. Day 18: Transverse image of the first detection of an anechoic gestational sac. Day 21: Longitudinal image of the gestational sac. An echogenic inner placental layer was detected in the uterine wall. Day 27: Longitudinal image of the gestational sac contained an embryo and the tubular shape of the yolk sac membrane (white arrows). The zonary placenta (white arrowheads) was cylindrical in shape and appeared folded inward at the edges. Day 28: The amnionic membrane (white arrows) appeared faint.

• 

  Fig. 2 Ultrasonograms of the fetal structures in pregnant Miniature Schnauzer bitches. Day 23: Transverse image of the gestational sac contained an oblong-shaped embryo (white arrowhead) apposed to the uterine wall. Day 32: Longitudinal image of a fetus with an anechoic area in the head and forelimb buds (white arrowheads). The fetal crown-rump length was 20 mm. Day 38: Longitudinal image of a fetus with hyperechoic skeletal structures in the head and thoracic wall (white arrowheads). Day 45: Longitudinal image of a fetal vertebral column and kidney (white arrowheads).

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