Abstract:

Reproductive success is a critical component of the care of bottlenose dolphins (Tursiops truncatus) in managed care facilities and is vital in sustaining free-ranging dolphin populations. Despite well-established breeding programs with high reproductive success rates, pregnancy failures still occur in managed care just as they do in free ranging dolphin populations. The purpose of this longitudinal study was to report ultrasound measurements and descriptive findings correlated with unsuccessful pregnancies. From 1996-2019, serial ultrasonographic evaluations of 16 dolphins in managed care were performed over 22 pregnancies. A total of 296 ultrasound exams were conducted, including parameters such as fetal biparietal diameter (BPD), thoracic width, thoracic height, aortic diameter, blubber thickness, and uteroplacental thickness.

Suggested Citation:

Forrest M. Gomez, Whitney B. Musser, Jennifer M. Meegan, Abraham Cárdenas Llerenas, Eric D. Jensen, Cynthia R. Smith. 2019. Ultrasonographic findings associated with failed pregnancy in the bottlenose dolphin (Tursiops truncatus). Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/n7-zsd3-he25

Purpose:

The purpose of this longitudinal study was to report ultrasound measurements and descriptive findings correlated with unsuccessful pregnancies.

Data Parameters and Units:

Exam.ID Unique identification number for each reproductive ultrasound (US) exam conducted Animal.ID Unique identification number for each dolphin in the dataset Exam.date Date of the exam (month/day/year) Parturition.date Date of parturition (month/day/year) Est.fetal.age.biparietal Estimated fetal age based on the biparietal diameter (BPD; cm) on the date of the exam (days) calculated using the following equation: gestational age (days) = 380-(348.16-(26.03*BPD)) Est.due.date Estimated due date based on estimated date of conception assuming a gestation of 380 days (month/day/year) Est.conception.date Estimated date of conception based on available data (earliest biparietal diameter, hormones, ovulation, socialization, paternity) (month/day/year) Est.fetal.age.380 Estimated fetal age on date of exam based on the estimated due date (days) GH.side Gravid uterine horn: Left (L) or Right (R) Fetal.sex Sex of fetus determined by resultant calf: Male (M) or Female (F) L.ovary.eval Left ovary evaluated: Y/N LO.condition Condition of the left ovary as determined by veterinarian's examination: Normal or Abnormal LO.activity Activity of the left ovary as determined by veterinarian's examination: Active or Quiescent LO.follicles Presence of follicles on the left ovary: Y/N LO.fol.num If follicles are present on the left ovary, how many: 1, 2 or >3 LO.fol.max.diameter If follicles are present on the left ovary, the maximum diameter of the dominant follicle (cm) LO.CL Presence of CL on the left ovary: Y/N LO.CL.max.diameter If a CL is present on the left ovary, the maximum diameter (cm) LO.CL.orth.diameter If a CL is present on the left ovary, the orthogonal to the maximum diameter (cm) LO.CS If a CL is present on the left ovary, are cyst-like structure(s) present: Y/N LO.CS.max.diameter If cyst-like structure(s) are present on the left ovary, the maximum diameter (cm) LO.CS.orth.diameter If cyst-like structure(s) are present on the left ovary, the orthogonal to the maximum diameter (cm) LO.CS.multiple If cyst-like structure(s) are present on the left ovary, are there more than 1: Y/N R.ovary.eval Right ovary evaluated: Y/N RO.condition Condition of the right ovary as determined by veterinarian's examination: Normal or Abnormal RO.activity Activity of the right ovary as determined by veterinarian's examination: Active or Quiescent RO.follicles Presence of follicles on the right ovary: Y/N RO.fol.num If follicles are present on the right ovary, how many: 1, 2 or >3 RO.fol.max.diameter If follicles are present on the right ovary, the maximum diameter of the dominant follicle (cm) RO.CL Presence of CL on the right ovary: Y/N RO.CL.max.diameter If a CL is present on the right ovary, the maximum diameter (cm) RO.CL.orth.diameter If a CL is present on the right ovary, the orthogonal to the maximum diameter (cm) RO.CS If a CL is present on the right ovary, are cyst-like structure(s) present: Y/N RO.CS.max.diameter If cyst-like structure(s) are present on the right ovary, the maximum diameter (cm) RO.CS.orth.diameter If cyst-like structure(s) are present on the right ovary, the orthogonal to the maximum diameter (cm) RO.CS.multiple If cyst-like structure(s) are present on the right ovary, are there more than 1: Y/N L.GHP.eval Gravid uterine horn and placenta evaluated scanning on the left side of the animal: Y/N L.UPU.cranial Mean thickness of the 'cranial' UPU of the gravid uterine horn scanning on the left side of the animal (cm). Measurements were obtained in triplicate, separated by 0.5cm in the 1st trimester and 1.0cm thereafter. 'Cranial' was the most cranial uterine margin in contact with the dam's body wall. L.UPU.cranial.max Maximum thickness of the 'cranial' UPU of the gravid uterine horn scanning on the left side of the animal (cm). 'Cranial' was the most cranial uterine margin in contact with the dam's body wall. L.UPU.cranial.min Minimum thickness of the 'cranial' UPU of the gravid uterine horn scanning on the left side of the animal (cm). 'Cranial' was the most cranial uterine margin in contact with the dam's body wall. L.UPU.mid Mean thickness of the 'mid' UPU of the gravid uterine horn scanning on the left side of the animal (cm). Measurements were obtained in triplicate, separated by 0.5cm in the 1st trimester and 1.0cm thereafter. 'Mid' was the subjective midpoint between 'cranial' and 'caudal' UPU and was not measured during the 1st trimester due to small uterine size. L.UPU.mid.max Maximum thickness of the 'mid' UPU of the gravid uterine horn scanning on the left side of the animal (cm). 'Mid' was the subjective midpoint between 'cranial' and 'caudal' UPU and was not measured during the 1st trimester due to small uterine size. L.UPU.mid.min Minimum thickness of the 'mid' UPU of the gravid uterine horn scanning on the left side of the animal (cm). 'Mid' was the subjective midpoint between 'cranial' and 'caudal' UPU and was not measured during the 1st trimester due to small uterine size. L.UPU.caudal Mean thickness of the 'caudal' UPU of the gravid uterine horn scanning on the left side of the animal (cm). Measurements were obtained in triplicate, separated by 0.5cm in the 1st trimester and 1.0cm thereafter. 'Caudal' was just cranial to the normal broadening of the UPU seen near the ovary. L.UPU.caudal.max Maximum thickness of the 'caudal' UPU of the gravid uterine horn scanning on the left side of the animal (cm). 'Caudal' was just cranial to the normal broadening of the UPU seen near the ovary. L.UPU.caudal.min Minimum thickness of the 'caudal' UPU of the gravid uterine horn scanning on the left side of the animal (cm). 'Caudal' was just cranial to the normal broadening of the UPU seen near the ovary. R.GHP.eval Gravid uterine horn and placenta evaluated scanning on the right side of the animal: Y/N R.UPU.cranial Mean thickness of the 'cranial' UPU of the gravid uterine horn scanning on the right side of the animal (cm). Measurements were obtained in triplicate, separated by 0.5cm in the 1st trimester and 1.0cm thereafter. 'Cranial' was the most cranial uterine margin in contact with the dam's body wall. R.UPU.cranial.max Maximum thickness of the 'cranial' UPU of the gravid uterine horn scanning on the right side of the animal (cm). 'Cranial' was the most cranial uterine margin in contact with the dam's body wall. R.UPU.cranial.min Minimum thickness of the 'cranial' UPU of the gravid uterine horn scanning on the right side of the animal (cm). 'Cranial' was the most cranial uterine margin in contact with the dam's body wall. R.UPU.mid Mean thickness of the 'mid' UPU of the gravid uterine horn scanning on the right side of the animal (cm). Measurements were obtained in triplicate, separated by 0.5cm in the 1st trimester and 1.0cm thereafter. 'Mid' was the subjective midpoint between 'cranial' and 'caudal' UPU and was not measured during the 1st trimester due to small uterine size. R.UPU.mid.max Maximum thickness of the 'mid' UPU of the gravid uterine horn scanning on the right side of the animal (cm). 'Mid' was the subjective midpoint between 'cranial' and 'caudal' UPU and was not measured during the 1st trimester due to small uterine size. R.UPU.mid.min Minimum thickness of the 'mid' UPU of the gravid uterine horn scanning on the right side of the animal (cm). 'Mid' was the subjective midpoint between 'cranial' and 'caudal' UPU and was not measured during the 1st trimester due to small uterine size. R.UPU.caudal Mean thickness of the 'caudal' UPU of the gravid uterine horn scanning on the right side of the animal (cm). Measurements were obtained in triplicate, separated by 0.5cm in the 1st trimester and 1.0cm thereafter. 'Caudal' was just cranial to the normal broadening of the UPU seen near the ovary. R.UPU.caudal.max Maximum thickness of the 'caudal' UPU of the gravid uterine horn scanning on the right side of the animal (cm). 'Caudal' was just cranial to the normal broadening of the UPU seen near the ovary. R.UPU.caudal.min Minimum thickness of the 'caudal' UPU of the gravid uterine horn scanning on the right side of the animal (cm). 'Caudal' was just cranial to the normal broadening of the UPU seen near the ovary. Umb.eval Umbilical cord evaluated: Y/N Umb.vessels Number of blood vessels visualized in umbilical cord (n) Umb.max.diameter Maximum diameter of the umbilical cord in cross-section at the site of fetal attachment (cm) Umb.abns Presence of umbilical cord abnormalities: Y/N Umb.abns.descr Description of any umbilical cord abnormalities Umb.doppler Blood flow confirmed by colorflow doppler: Y/N Umb.urachus Urachus (allantoic duct) visualized in umbilical cord: Y/N Umb.fetal.att Fetal attachment of the umbilical cord visualized: Y/N Umb.placental.att Placental attachment of the umbilical cord visualized: Y/N Fluid.eval Uterine fluid evaluated: Y/N Uterine.fluid If amniotic and allantoic fluid cannot be distinguished, echogenicity of uterine fluid: Anechoic, Hypoechoic or Hyperechoic UF.FFPs Presence of free floating particles (FFPs) in uterine fluid: Y/N UF.max.depth Maximum depth of uterine fluid (cm) All.fluid Echogenicity of the allantoic fluid: Anechoic, Hypoechoic or Hyperechoic All.FFPs Presence of free floating particles (FFPs) in allantoic fluid: Y/N All.max.depth Maximum depth of allantoic fluid (cm) Amn.fluid Echogenicity of the amniotic fluid: Anechoic, Hypoechoic or Hyperechoic Amn.FFPs Presence of free floating particles (FFPs) in amniotic fluid: Y/N Amn.max.depth Maximum depth of amniotic fluid (cm) Fetus.eval Fetus evaluated: Y/N Biparietal.diameter Biparietal diameter (cm) Trimester.number Trimester: 1st, 2nd or 3rd Thorax.dorsal Thoracic diameter measured at the level of the heart left-to-right in a dorsal plane (cm) Thorax.sagittal Thoracic diameter measured at the level of the heart dorsal-to-ventral in a sagittal plane (cm) Thorax.transverse Thoracic diameter measured at the level of the heart left-to-right in a transverse plane (cm) Fetal.sex.us Fetal sex determined ultrasonographically in utero if genitalia could be identified: Male (M) or Female (F) Cardiac.movement Detection of fetal cardiac movement: Y/N Mmode.HR Mean fetal heart rate, obtained in triplicate, calculated in M-mode (bpm) Aorta.diameter Mean aortic diameter, measured in triplicate, from lumen-to-lumen close to the heart (cm) Eye.max.diameter Maximum diameter of the fetal eye globe spanning the inner margins of the vitreous body (cm) Eye.orth.diameter Orthogonal to the maximum diameter of the fetal eye globe spanning the inner margins of the vitreous body (cm) Fetal.movement Fetal movement subjectively graded by veterinarian: None, Rare, Frequent or Continuous Pleural.effusion Presence of pleural effusion: Y/N Heart.abns Presence of abnormalities of the heart: Y/N Lung.echo Echogenicity of the lung as compared to the echogenicity of the liver: Hyperechoic, Hypoechoic or Isoechoic Lung.homog Homogeneity of the lung tissue: Homogeneous or Heterogeneous Lung.MPI Mean pixel intensity (MPI), a unitless value to quantify echogenicity, of the lung tissue. This value is calculated using an 8-bit grayscale with 256 shades of gray. Liver.MPI Mean pixel intensity (MPI), a unitless value to quantify echogenicity, of the liver tissue. This value is calculated using an 8-bit grayscale with 256 shades of gray. MPI.ratio Calculated lung/liver ratio of mean pixel intensity (MPI) Peritoneal.effusion Presence of peritoneal effusion in the abdomen: Y/N Hyperechoic.abdomen Presence of hyperechoic foci in the abdomen: Y/N Hyperechoic.abdom.grade If hyperechoic abdomen present, subjectively graded by echogenicity: 1, 2 or 3 Forestomach.fluid Presence of fluid in the forestomach: Y/N Kidney.abns Presence of abnormalities of the kidneys: Y/N Bladder.abns Presence of abnormalities of the bladder: Y/N Bladder.fluid Presence of fluid in the bladder: Y/N Blubber.thickness Thickness of the blubber layer measured close to the level of the heart on the dorsum (cm) Maternal.abdominal.effusion Presence of maternal abdominal effusion: Y/N Mat.abdom.eff.grade If maternal abdominal effusion is present, subjectively graded: Scant, Mild, Moderate or Severe

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