Pregnancy Diagnosis in the Mare Flashcards
How can we PD in the mare? (7)
- Failure to return to oestrus - day 18-24
- (Elevated plasma progesterone day 18-20)
- Transrectal ultrasound from day 12 (15 common)
- Transrectal palpation from day 21
- Plasma equine chorionic gonadotrophin from day 60 – 120
- Transrectal ballottement of foetus from day 80
- (Plasma or urine oestrogen from day 150)
Why can we not PD the mare before day 17?
•Before day 17 the conceptus moves around the uterus 0 they are moving around because the job of the embryo is to provide signal to mother that is is pregnant. Needs MR so black prostaglandin production so the early phase of this spherical conceptus it moves around uterus telling the mare it is there. When we come to an early PD – do a complete exam from one ovary to other and down uterus body. Might be a conceptus anywhere. Not until day 17 is it so large it cannot move about- this is in base of a horn
What is different about the PD in a cow and horse?
•Might not be that useful because at 21d you feel for focal swelling in uterus in base of horn, in cows its different and can feel difference in size of horn, but in cow it’s a swelling in base of one horn – challenge is if both conceptus is same horn, wont be able to tell there are twins – just that there is a swelling! If they are in separate horns – will feel 2 swellings If you try and squeeze it at this stage and liberate the fluid – a lot more fluid here! This fluid shouldn’t be there and free membranes floating around and if you cause this, the uterus will have a response and likely release prostaglandin and likely the other conceptus will be lost. So the earlier you squeeze them, the smaller the fluid is released and more likely to success
What can give us the hint of twins in a horse?
•two large follicles when US at oestrus =2 CLs and this could mean both could ovulate = twins
How can rectal palpation be used to PD?
–Pregnancy specific enlargement of the uterus
•What is the consequence of pregnancy loss
–Before maternal recognition?
–After maternal recognition but before day 40?
–Before maternal recognition?
•Return to oestrus (dam doesn’t know she was pregnant)
–After maternal recognition but before day 40?
- Signal produced, and PG blocked longer luteal phase.
- 2 types of psudopreg
Why isn’t mummification so common in foals?
As fetal death tends to happen later
What does this show?
Equine CL – CL
What does this show?
Bovine CL
•How can you differentiate a pregnancy from an endometrial cyst?
- 14 days conceptus is spherical
- Bright echo – reflections (specular)
- Count the number of CLs
- When you look at the middle one there is an enlongation which makes us suspicious of at least 1 cyst
- If we scanned her when to be bred we would have made a note and have prior knowledge prior to scan
- If we scan this mare tomorrow – might have moved or gotten bigger if pregnancy. If a cyst – wont have moved or grown.
How can we confirm the diagnosis of mare twins?
Through a careful exam
Why are these twins of different sizes?
- Ovulated on different days
- 15 and 13 day pregnancy
What does this show?
Schematic equine conceptus development
What is this?
Schematic equine conceptus development
•Is the placenta detaching?
- Two fluid components
- Top – yolk sac
- Bottom – allantois
- Not placenta detach
- Just progression of allantois and regression of yolk sac!
- Can even see heart beat
What are the days of this Schematic equine conceptus development?
Day 30 and 35
What is different here?
Lost spherical
Not turgid
What day of the conceptus is this schematic?
50
What do we do here?
- Circular 15 mm conceptuses = 15 days post ovulation
- = conceptuses mobile and can therefore be separated and one can be crushed
What is this?
Twins at 14 and 15 days
What is this?
Twins at 17 days
