Lecture 13: Preg Dx and gestational problems in cows Flashcards Preview

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0

average conception rate of cows in the US?

30% - must do preg dx weekly!

1

** palpation per rectum **

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

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

--> doesn't tell you about viability

2

direct methods of dx pregnancy

(feel or see!)
- ballottement of fetus
- palpation per rectum
- ultrasound

3

indirect methods of dx pregnancy

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

4

when should you measure progesterone when diagnosing pregnancy?

at day 21 - should be HIGH if pregnant

5

how long is the luteal phase in cows?

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

6

dx pregnancy via PCR method

interferon-t stimulated genes

pregnancy recognition mechanism in cows is interferon-tau

7

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

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)

8

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

9

fremitus =

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

it hypertrophies during pregnancy

10

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

11

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

12

** 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

13

fetal sexing

genital tubercle - sex around 60 days

close to umbilicus = male
base of the tail = female

14

what are the 3 hormonal methods of dx pregnancy

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

15

progesterone in blood or milk to dx pregnancy

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

16

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

good indicator of pregnancy as early as 30 days of gestation

17

** fetal mummification **

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

** no bacteria - an aseptic condition **

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

18

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

19

** 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***

20

***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

21

uterine torsion

occurs during 1st stage of parturition!

22

methods of correcting uterine torsions

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

23

***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

24

prolapsed vagina

occurs pre-partum in late gestation when estrogen is HIGH

25

prolapsed uterus: 3 main causes

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