Lecture 13: Preg Dx and gestational problems in cows

Question 0

** palpation per rectum **

Answer 0

**membrane slip - chorioallantois **
amniotic vesicle
fetus
placentomes

**2,2 - two fetus, two membrane indicators **

–> doesn’t tell you about viability

Question 1

average conception rate of cows in the US?

Answer 1

30% - must do preg dx weekly!

Question 2

direct methods of dx pregnancy

Answer 2

(feel or see!)

• ballottement of fetus
• palpation per rectum
• ultrasound

Question 3

indirect methods of dx pregnancy

Answer 3

• history: non-return to estrus; anestrus
• physical changes in dam (mammary development)
• endocrine (P4) changes in milk or blood

Question 4

when should you measure progesterone when diagnosing pregnancy?

Answer 4

at day 21 - should be HIGH if pregnant

Question 5

how long is the luteal phase in cows?

Answer 5

14 days - progesterone should come down when the cow comes back into estrus

Question 6

dx pregnancy via PCR method

Answer 6

interferon-t stimulated genes

pregnancy recognition mechanism in cows is interferon-tau

Question 7

what are the 4 positive signs of pregnancy when palpating per rectum

Answer 7

1. fetal membrane slip (chorioallantois)
2. amniotic vesicle (feel from 35 days up to 65 days)
3. fetus
4. placentomes (start to actually feel at 90 days)

Question 8

what other things should you look for when dx pregnancy per rectum?

Answer 8

asymmetry of uterine horns
fluctuance (not always pregnant - could be pyo or hydrometra)
fremitus

Question 9

fremitus =

Answer 9

buzz of artery during palpation - the middle uterine artery (which is a branch off the internal iliac artery)

it hypertrophies during pregnancy

Question 10

earliest possible detection of: 
membrane slip
amniotic vesicle
fetus
placentomees
fremitus

Answer 10

membrane slip = > 30 days
amniotic vesicle = 35 - 65 days
fetus > 65 fays
placentomes > 3 months (90 days)
fremitus > 3.5 months

Question 11

aging fetuses at necropsy based on size: 
60 d = 
120 d = 
180 d = 
210 d =

Answer 11

60 days = mouse
120 days = cat
180 days = beagle
210 = german shepherd

Question 12

** how do you age an amniotic vesicle**

Answer 12

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

Question 13

fetal sexing

Answer 13

genital tubercle - sex around 60 days

close to umbilicus = male
base of the tail = female

Question 14

what are the 3 hormonal methods of dx pregnancy

Answer 14

1. progesterone in blood or milk
2. pregnancy spceific protein (PSPB) or pregnancy associated glycoprotein (PAG)
3. interferon tau stimulated genes

Question 15

progesterone in blood or milk to dx pregnancy

Answer 15

1. sample at time of AI (P4 should be low)
2. sample 23 days later (P4 should be high)
3. 99% effective in identifying “open” cows

Question 16

pregnancy specific protein (PSPB) or pregnancy associated glycoprotein (PAG)

Answer 16

good indicator of pregnancy as early as 30 days of gestation

Question 17

** fetal mummification **

Answer 17

** rare; occurs around 4 -6 months **

** no bacteria - an aseptic condition **

** causes: not quite sure why it happens **

Question 18

how do you treat fetal mummification

Answer 18

prostaglandin –> lyses the CL, cow will come into heat in 3 - 5 days –> cervix will relax –> uterus contracts and mummy is expelled

Question 19

** hydrops allantois **

Answer 19

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***

Question 20

hydrops amni

Answer 20

**a fetal anomaly - impaired deglutition of renal dysgenesis or agenesis –> gradual accumulation of amniotic fluid **

pear shaped abdomen

fetus and placentomes CAN be palpated

Question 21

uterine torsion

Answer 21

occurs during 1st stage of parturition!

Question 22

methods of correcting uterine torsions

Answer 22

1. manual torsion per vaginam
2. rolling the cow
3. fetal extraction

Question 23

when extracting fetus during uterine torsion….

Answer 23

*** 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

Question 24

prolapsed vagina

Answer 24

occurs pre-partum in late gestation when estrogen is HIGH

Question 25

prolapsed uterus: 3 main causes

Answer 25

post-partum flaccid uterus with continued abdominal contraction after calving
uterine inertia:
1. hypocalcemia - the major risk factor
2. large calf - stretches the uterus
3. dystocia