Lecture 13: Preg Dx and gestational problems in cows Flashcards
** palpation per rectum **
**membrane slip - chorioallantois **
amniotic vesicle
fetus
placentomes
**2,2 - two fetus, two membrane indicators **
–> doesn’t tell you about viability
average conception rate of cows in the US?
30% - must do preg dx weekly!
direct methods of dx pregnancy
(feel or see!)
- ballottement of fetus
- palpation per rectum
- ultrasound
indirect methods of dx pregnancy
- history: non-return to estrus; anestrus
- physical changes in dam (mammary development)
- endocrine (P4) changes in milk or blood
when should you measure progesterone when diagnosing pregnancy?
at day 21 - should be HIGH if pregnant
how long is the luteal phase in cows?
14 days - progesterone should come down when the cow comes back into estrus
dx pregnancy via PCR method
interferon-t stimulated genes
pregnancy recognition mechanism in cows is interferon-tau
what are the 4 positive signs of pregnancy when palpating per rectum
- fetal membrane slip (chorioallantois)
- amniotic vesicle (feel from 35 days up to 65 days)
- fetus
- placentomes (start to actually feel at 90 days)
what other things should you look for when dx pregnancy per rectum?
asymmetry of uterine horns
fluctuance (not always pregnant - could be pyo or hydrometra)
fremitus
fremitus =
buzz of artery during palpation - the middle uterine artery (which is a branch off the internal iliac artery)
it hypertrophies during pregnancy
earliest possible detection of: membrane slip amniotic vesicle fetus placentomees fremitus
membrane slip = > 30 days amniotic vesicle = 35 - 65 days fetus > 65 fays placentomes > 3 months (90 days) fremitus > 3.5 months
aging fetuses at necropsy based on size: 60 d = 120 d = 180 d = 210 d =
60 days = mouse
120 days = cat
180 days = beagle
210 = german shepherd
** how do you age an amniotic vesicle**
take the width of the amniotic vesicle (via the squares, 5mm per square) and add 20
ex: fetus is about 12mm + 20 = 32 days
–> this method works up until about 50 days
fetal sexing
genital tubercle - sex around 60 days
close to umbilicus = male
base of the tail = female
what are the 3 hormonal methods of dx pregnancy
- progesterone in blood or milk
- pregnancy spceific protein (PSPB) or pregnancy associated glycoprotein (PAG)
- interferon tau stimulated genes
progesterone in blood or milk to dx pregnancy
- sample at time of AI (P4 should be low)
- sample 23 days later (P4 should be high)
- 99% effective in identifying “open” cows
pregnancy specific protein (PSPB) or pregnancy associated glycoprotein (PAG)
good indicator of pregnancy as early as 30 days of gestation
** fetal mummification **
** rare; occurs around 4 -6 months **
** no bacteria - an aseptic condition **
** causes: not quite sure why it happens **
how do you treat fetal mummification
prostaglandin –> lyses the CL, cow will come into heat in 3 - 5 days –> cervix will relax –> uterus contracts and mummy is expelled
** hydrops allantois **
much more common than amni
- rapid overproduction of allantoic fluid***
- adventitial placentation - looks splotchy***
- tight uterine walls - cannot palpate placentomes and fetus ***
- may be related to vitamin E/Selenium deficiency***
hydrops amni
**a fetal anomaly - impaired deglutition of renal dysgenesis or agenesis –> gradual accumulation of amniotic fluid **
pear shaped abdomen
fetus and placentomes CAN be palpated
uterine torsion
occurs during 1st stage of parturition!
methods of correcting uterine torsions
- manual torsion per vaginam
- rolling the cow
- fetal extraction
when extracting fetus during uterine torsion….
*** depending on degree of cervical dilation - need to give dam some time after the correction to see how it will proceed –> spend time dilating the cervix
