Optimal Breeding Time in The Mare Flashcards
- 17 year old warmblood mare
- Retired from work due to an orthopaedic injury
- Owner now wishes to breed from her
- What other questions do you you need to ask the client prior to examining this mare?
•Has she been bred before?
–17 yo maiden mare is a worse prospect
- Is she foaled before was it easy?
- Temperament?
- Any other concurrent disease?
–E.g.PPID – affects fertility, if you get her in foal will affect lactation
•How severe is the otrthopaedic issue?
–Is she in cast and cant move – wont be covered naturally be a stallion?
–Chronic lame – co morbidity
- Is she a maiden mare?
- Has she been covered before?
–If yes, what is her reproductive history?
•Does she have any concurrent disease?
–Will the severity of her orthopaedic disease be an issue?
–PIPD?
•What is your stallion choice?
–Fresh/ chilled/frozen
•Fresh survives longer and has a better success rate
–From where in the world
–Fertility/age of stallion
–Younger tend to be more fertile
–Better to us a stallion with a good fertility record
•What health tests/ screens do you need to consider before she arrives at stud?
What intitial tests can we do and how do we test for this?
Which are notifiable?
Contagious Equine Metritis - Clitoral Swabs
Equine Viral Arteritis- Serum
Equine Infectious Anaemia- Serum
(Strep equi var equi- Serum
- You perform a general clinical exam.
- Is there anything which could stop this mare from carrying a foal to term and raising it to weaning?
- Line stifle to fetlock shouldn’t be this straight
- Dropped fetlock – suspensory too long
–Probably degenerative
–Weight of foal will make this horse struggle towards end
•What are your thoughts on the vulval conformation in this mare?
What is the effect of this and how can we deal with it?
–Common in old poor BCS
–Vulva is sloped and loose the vulval seal; contamination of repro tract with faeces and urine = compromised fertility. Fail to conceive or early pregnancy loss risk factor
- Sunken vulval conformation
- Leads to contamination of the reproductive tract with faecal material/urine
- Prevented by Caslicks procedure
–(Covered in practical session)
What other evaluations would you carry out to this mares reproductive tract? (4)
•Aim to gather as much information as possible
–Gives owner realistic expectations of how easy this mare may be to get in foal.
–The costs involved.
•Rectal Exam
–Palpate uterus and ovaries
- Speculum Exam of cervix.
- Endometrial Swab for culture and cytology.
- Uterine biopsy?
–Grade for fibrosis – tells us how likely mare is to be fertile
–Can do uterine endoscope to look at surface!
- Always look at oedema pattern across uterus, check for endomertail fluid, look t each ovary in term – look for CL and looking at any follicles and measuring any of significance (25mm).
- Feel and look at cervix to have estimation of oestrus cycle by assessing tone of cervix and how open.
- First scan
- What do you think of the following images
- Uterine oedema pattern – Not much oedema. Look at how strippy the uterus is. The more stipey/more like orange segment – more oedema.
- Ovary – CL the white structure, the black holes to the right are small follicles (under 25mm)
- Progesterone dominant phase – from CL
Your first exam reveals the following:
•Examination per rectum
–Toned cervix, no uterine oedema (grade 0/3)
–Small follicles both ovaries ~20mm
–Corpus Luteum
•Palpation of cervix
–Toned and closed
•What stage of the reproductive cycle is the mare in and how would you proceed?
–Progesterone dominant
–Wait for her to come in naturally - but O doesn’t want to pay to stay at stud
Give PG and have another look in 4-5 days
•The mare is in dioestrus
–Progesterone dominance.
What d you admnister?
•Administer prostaglandin IM and re-examine in 4-5 days
What are your thoughts on these?
- Uterine oedema – grade 2 (more stripes developing)
- No measurements. Follicle at bottom looks a bit bigger. Ovary doesn’t fit well onscreen. If you measured would expect at least one dominant
•Follicles have developed, increasing in size.
–Is one becoming dominant?
- CL is no longer visible
- Uterine oedema is 2/3
- Cervix is softer and opening
What stage is the mare in? What do we do next?
•The mare is in early oestrus (oestrus is 5 days so you still have time!)
–Wait and scan in 1-2 days
- These images were obtained a further 2 days later
- What are your thoughts?
–Ovary – dominant follicle! All you can see is a huge follicle which is over 35mm (round and no speckles, hypoechogenic). No CL visible.
–Uterus is stripey. Lots of oedema and endometrium olded over.
–Cervix – will be dilated. In a mare who has never foaled before this may not be as dilate as an older one.
- Rectal reveals a 35mm follicle
- Uterine oedema 3/3
- Cervix is soft and dilated
What stage is the mare in?
Oestrus
When does natrual ovulation occur? (before end of oestrus)
•Natural ovulation occurs 24 hrs. before end of oestrus (difficult to predict exactly when she will ovulate)
When does defrosted semen need to meet an egg?
Within 6 hours
What ovulation agents can we use and what is the time to oestrus? (2)
What do we do after giving ovulation inducing agents?
•Scan mare repeatedly over that time frame and inseminate as soon as ovulation occurs. As soon as she ovulates you inseminate! 90% read the textbook and ovulate as above.
•What will we look for on our post insemination scan?
–Look at uterus and look for oedema
–Look for follicles CL and feel cervix
–This uterus – Fluid in the endometrium!. Common post insemination (particularly with frozen semen)
–Ovary – 2 CLs; had a second ovulation at some point important to know so when we scan in 15 days we can check notes to know when released 2 eggs. If both released at the same time she could have twins
What do we check in a post frozen semen insemination? (4)
- Quality of CL
- Have there been any secondary ovulations making twins a possibility.
- Post mating endometritis treatment
–Uterine lavage – sterile saline through catheter. Remove and dilate uterus inflammatory fluid
–Oxytocin- induce uterine contractions to force fluid out whilst at end of oestrus with open cervix
–Intra-uterine antibiotics – based on swab when she first arrive
•Caslicks? – limit bacterial contamination of uterus and increase the chances to receive embryo
- You ask for the mare to return 15 days post ovulation for a pregnancy diagnosis scan
- This reveals
–CL present
–Multiple small follicles
–No pregnancy
•How will you proceed?
–Likely to come back in 21 days after first ovulation. So have about 6 days before ovulation. Don’t need to do anything or give PG.
•Owner decides to switch to a local 7 year old stallion
–Stands locally
–Proven good fertility
–Fresh semen available
- Likely to come back in to season on day 21 of cycle
- Therefore should ovulate in approx. 6 days
- When should we inseminate when using fresh semen?
–The semen will last longer in the mare
–Can last up to 5 days cf frozen where you have 6 hours
–Mare can ovulate anytime in the 5 days and get pregnant
How long does fresh semen last?
at least 48 hours
When is fresh semen insemination done?
•Insemination is performed before ovulation
–12-36hrs prior to expected ovulation
–We still use ovulation inducing agents to time ovulation. So you know when likely to ovulate
How do you post mating exam with fresh semen?
•Post mating exam is as before although degree of post mating endometritis tends to be less with fresh/chilled semen cf frozen.
–Another reason to use a stallion or fresh! Especially in a mare you know has suffered previously
What do you see?
–One CL
–Multiple small ish follicles
–Scan and find this at the base of the horn: normal! 15 day pregnancy . Normal implant at base of horn. Fluid very black. Not worried
–Would then scan again at day 30 to see progression
