1.4.1 Pregnancy Flashcards
is failure to return to estrus a good predictor of pregnancy? why or why not?
Failure to return to estrus is a poor pregnancy test
False positives may be due to:
* Inaccurate estrus detection
* Missed estrus
* Not knowing signs of estrus
Prolonged diestrus or anestrus
* Cystic ovarian disease in cows
* Up to 20% of mares may have a prolonged luteal phase
* Signs of estrus in early pregnancy (~5%)
is false pregnancy common in horses?
- Common in some species
- NOT horses
what animals show false pregnancies? what are the associated behaviours?
- Canine – may show mammary development, lactation and nesting behaviour
- Caprine – develop enlarged abdomen, uterus full of fluid
> “cloud burst” or mucometra
are Blood Tests for Pregnancy Factors useful in the ruminant?
nope
why dont we commonly use blood test for pregnancy glycoproteins in ruminants?
even though they work somewhat ok, have a delay and can only be used after a certain time, eg. 73 days after postpartum and 30 days after insemination
is hormonal analysis useful for pregnancy detection in cows?
Not really
* Progesterone
* Low levels 19 – 21 days post breeding are suggestive of estrus and NON pregnancy
High levels do not confirm pregnancy
* Cannot differentiate from Diestrus
* Pyometra, mummified fetus etc.
* Progesterone is NOT a good pregnancy test
- Is progesterone a good pregnancy test in the mare?
no, it is not even the main pregnancy-sustaining hormone after about 120 days and will be very low even if she is pregnant
is eCG a good way to test for pregnancy in a mare? what are advantages and disadvantages?
- Test between 40 and 120 days
- Cups persist through 120 days even if
fetus dies = false positives - False negatives = tails of curve
- Too early in pregnancy
- Too late – after cups are gone
- Can use together with estrone sulfate – tandem assay repeated after 2‐4 wks
- If show rising levels of estrone, with continued presence of eCG, indicates live fetus, viable pregnancy
is estrogen sulfate a useful hormone to test for in the mare to diagnose pregnancy? if so, when?
Estrone sulfate (conjugated estrogen):
* Serum estrogens elevated as soon as Day 35‐40
* After Day 60 feto‐placental source
* Diagnostic of pregnancy by day 45 >6.0 ng/ml
(BEWARE THE MINI: day 80 >60.0 ng/ml)
* Can be used for fetal viability prior to 7 months gestation
is a progesterone test useful to diagnose pregnancy in the bitch? what might we use instead and is it useful?
- Progesterone is NOT useful (same diestrus phase whether pregnant or not)
- Relaxin hormone
- Witness® or ReproCheck®
- Produced by canine placenta – increases in pregnancy, NOT diestrus
- From days 22‐27 after breeding
- False positives and negatives can occur
what do we expect to feel on a <3 month pregnant cow? can we get a better age range and if so how?
- light cervix
- One horn bouncy and thin walled, 1”-3” dia, CL on same side ovary
> other horn no bounce and thick walled = 30 to 50 days - both horns bouncy, thin walled, same size; ballot fetus = 60-90 days
what do we expect to feel on a >3 month pregnant cow?
-ballot fetus
Assess size of cotyledons:
quarter = 3 mos
toonie = 4 mos
silver dollar = 5 mos
assess fremitus:
begins by pregnant horn at about 3-4 mos
both horns from 7 mos
The four absolute (definite) signs for bovine pregnancy on rectal palpation:
- Amniotic vesicle
- Fetal membrane slip
- Fetus
- Placentomes
what is fetal membrane slip? can it be felt in the hose?
slipping of chorio-alantois within uterus. cannot be felt in horse because horse has diffuse placenta
when in bovine pregnancy can we feel a fluid filled horn with CL on the same side?
heifers: 30d
cows: 30-40d
when in bovine pregnancy can we feel a fetal membrane slip?
> 30d
when in bovine pregnancy can we ballot fetus?
> 70d
when in bovine pregnancy can we feel placentomes?
> d 80-90
when in bovine pregnancy can we feel fremitus?
> d 80-120
what is fremitus? significance?
- “buzzing” of the middle uterine artery within broad lig.
- Apply slight pressure to artery to feel
- Associated with pregnancy but not definitive
how can we estimate the gestational age in cows based on horn diameter? size of fetus?
Horn diameter:
* Day 30 – 1 in. diameter
* Day 60 – 3 in. diameter
* Day 90 – 6 in. diameter
Size of fetus:
* Day 60 – large mouse
* Day 90 – rat
* Day 120 – cat
what will the uterus feel like upon palpation in the mare during pregnancy?
- Increase in cervical and uterine tone
> Usually by day 15‐18
when during a mare’s pregnancy can we detect a bulge at the base of the uterine horn? where, exactly?
- Detect bulge at the base of uterine horn
- Ventral aspect
- By day 20‐25
when during a mare’s pregnancy will we be able to ballot the fetus?
- Day 90‐120
