Lecture 2 Flashcards
(47 cards)
What is the purpose of pregnancy diagnosis in the mare
- To confirm pregnancy
- Distinguish between single and multiple conceptus
- Detect early embryonic death and manage a return to oestrus where early embryonic death is recorded
What are the methods of pregnancy diagnosis in the mare
- Behavioural assessment
- Lab tests
- Rectal palpation
- Ultrasonogrpahy
- Abdominal ballottement
- Oberservation - udder, change in shape of abdomen
What does behavioural assessment indicate
- Non-specific indicator of pregnancy
- Mares normally return to oestrus 16-20 days post ovulation
What does failure to return to oestrus indicate
Pregnancy
Behavioural assessment: false positive
Persistent luteal function, early embryonic death, failure to show signs of oestrus, anoestrus
Behavioural assessment: false negatives
Some pregnant mares can show behavioural signs of oestrus
What is a tease negative
Tease out - mare is visibly resistant to stallion
What is tease neutral
Passive - mare is indifferent/passive in presence of stallion
What is tease positive
Tease in - mare is interested in stallion; may urinate; wink vulva, squat, lean into stallion
What is the vaginal speculum examination
Examination of cervix 18-21 days after ovulation. It is non-specific indicator of pregnancy
What does a high, dry, tight and white cervix suggest
Dioestrus
What is progesterone produced by
CL
What do you collect with lab test and when
Test milk or plasma at time of expected return to oestrus
What do high concentrations indicate of progesterone
Presence of CL
How do you get a false negative with lab tests
Persistent CL function, embryonic death
When is equine chorionic gonadotrophin first produced by
Endometrial cups from days 36-40 of gestation
How long is equine chorionic gonadotrophin secreted for
up to 120 days of gestation
When do chorionic girdle cells develop around
25 days of gestation
When can cells from the chorionic girdle invade the endometrium
35 days
eCG - how you get a false positive
Foetal death occurs after endometrial cups have formed
eCG - how you get a false negative
Testing outside of the range of normal time for eCG production - sample taken too early
Explain Oestrgens of horse
Concentrations rise after day 60, peak at by 180 to 240 and then decline until parturition
What do oestrogen’s produce
Foetal-placental unit
What does a positive test of oestrogens indicate
Viable foetal-placental unit, so it can be test for foetal viability