Ultrasound In Dairy Practice Flashcards
What are US used for in diary cattle?
Access ovarian function
Dx pregnancy earlier
Detect twins
Determine fetal viability
Visualize pathology
Important US images
Early signs of fetal dz
Congenital fetal abnormalities
Ovarian and uterine pathology
Fetal sexing
Hyperechoic
Greater reflection of waves
Bones and other dense tissue
Hypoechoic
Fewer waves reflected
Soft tissue
Anechoic
Appears black
No waves returned
Fluid (early pregnancy)
Pregnancy can be detected as early as ____________
25-26d (now about 30-35)
allows for early resynchronization for open cows
Why are recheck exams essential?
EED rates of 8-10% for single pregnancies and 25% for twin pregnancies
Heartbeat is detected ________ gestation
28d
lack of heart beat= fetal demise
Detection of fetal viability
Echogenic debris within CA or amniotic fluid
Separation of fetal membranes from the wall of uterus
Irregularly shaped or hyperechoic embryo
ID of non viable fetus allows ____________
Quicker return to breeding eligibility (could be in there for days or weeks)
Examples of congenital anomalies
Multiple headed fetuses
Schistosomus reflexus
Anasarca
Fetal gender determination
Producers use to make management decisions: neonatal management, culling and AI contracts
55-90d gestation
What does fetal determination depend on?
Genital tubercle (migration complete by 55d)
Female genital tubercle
Bi-lobed, hyperechoic structure under the tail of bovine after 55d gestation
Male genital tubercle
Hyperechoic structure located immediately caudal to the umbilicus
Fetal aging
More precise prediction with unknown
More accurate than palpation alone
After 128d US less accurate for aging
Embryo is 1cm in length at _______
28d
Trunk diameter
Widest part of the rib cage at the level of umbilicus
Biparietal diameter
Maximum diameter of the skull @ the level of the eyes
Crown-rump length (CRL)
Up to 50d gestation age:
CRL (mm) + 18 = fetal age in days
Head length
Measures from crown of head to tip of nose
3 yr-old Holstein cow for pregnancy dx. Image of the tip of the uterine horn and ovary. What condition and therapy?
Presence of purulent fluid in uterine lumen
Prolonged lifespan of CL due to failure of leuteolysis
Tx: luteolytic dose of PGF2a
4 yr-old Holstein @ 85 DIM. What structures are seen? The other ovary is static and cow hasn’t shown signs of estrus. Management?
Anovular condition (no luteal tissue)
May exhibit repeated estrus
Tx: GnRH +/- TAI protocol
2 yr-old crossbred beef cow for pregnancy dx @ 110d after AI. IS this fetus normal? If not, abnormalities?
Fetal Ascites/ Anasarca
Ovarian enlargement ruleouts?
Granulosa Cell tumor- dx with AMH (produced by granulosa cells within DF)
