Equine Repro and Neonatology Flashcards
Over what age is classed as a mare?
> 4 years
Puberty at 12-24 months
How does a mare cycle?
It will struggle- ha hey
Long day
Seasonal polyoestrus
How long does the oestrus cycle last?
When does Diestrus/Oestrus occur?
Oestrus cycle- 21 days
Dioestrus- 16-17 dYS
Oestrus- 4-6 days
What is the equine transition period?
- Period of change from anoestrus to regular cycling
- Lasts upto 6 weeks
- Ovaries have multiple small follicles
- Can show no oestrus, constant or erratic oestrus
- Follicles will not ovulate
What can the following drugs be used to manipulate in oestrus?
1. Prostaglandins
2. Prostagens
3. Oestrogens
4. Chorionic gonadotrophin
5. Desleroelin
- Prostaglandins- induce luteolysis of CL: oestrus 3-5 days post injection
- Given orally suppress oestrus, withdrawal causes rebound activity
- Oestrogens: induce behavioural oestrus: AI collection
- Given during oestrus: induce the dominant follicle
- Hormone sub-cut induce ovulation within 48h
How can the photoperiod be used to manipulate oestrus?
- Can be brought forward by artificial light over winter
- Mares ovulate 8-10 weeks later
How can oestrus be suppressed?
- Long term progestagens- spenny
- Intrauterine devices- not encouraged
- Anti-GnRH vaccine- not licensed
- Induce long term CL- oxytocin
- Put in foal and terminate
- Ovariectomy: invasive, expensive
When should mares be served?
- Oestrus behaviour ceases within 24 hours of ovulation: mare no longer receptive
- Ooctye viable for 12 hours post ovualtion
- Matings after ovulation have poor conception
- Spermatozoa reach oviduct within hours and are viable for 48 hours
Serve mares 24-48 hours prior to ovulation
What structures will a mare in oestrus have?
- Dominant follicle
- Uterine oedema
- Soft oedematous cervix
- Behavioural signs of oestrus
If in oestrus scan 24-48h later
If not give PG: 3-5 days
What are the signs ovulation is abour to occur?
- Numerous to dominant follicle
- Dominant follicle- pointing (imminent)
Ovulated leaving corpus haemorrhagicum- CL
- If follicle >35mm, uterine oedema regressing: MATE
What should be scanned post mating?
- 12-24 hours after
- See if ovulated
- Check for one ovulation: twins
- Fluid in uterine lumen: endometritis
What does bad perineal conformation lead to?
- Failure of vulval and vestibular seal
- Pnuemovagina
- Cervicitis
- Bacterial contamination
- Endometritis
How can perineal conformation be altered?
Caslicks vulcoplasty
* Closure of vulva
* Requires opening before foaling
What ovarian problems can occur?
Persistent CL- tx: PG
Anovulatory follicles: tx PG/time
Granulosa cell tumour- lymphomania or anoestrus: AMH
Whar are the effects of endometritis?
Does not affect conception but implantation
Chronic metritis, free fluid, mating induced endometritis
How is endometritis treated?
- Uterine lavage: volumes of saline
- Oxytocin
- Intrauterine ABs
- Use of AI
What is chronic degenerative endometrial disease?
Endometriosis
* Progressive degen of endometrium and replacement by fibrotic tissue
* Age related infertility
DX: hisopath
TX: none/curette
- What causes cervical incompetence?
- What are the problems with uterine cysts?
- Either congenital or foaling injury- Sx
- Rarely cause infertility, can cause problems at preg- remain static in size
What pre-breeding diseases are cleared?
- Clitoral swab for CEM: contagious equine metritis
- Blood sample for EVA: equine viral arteritis
- Strangles
How long is a horse pregnant?
336 days average
What do endometrial cups do?
- Endometrial cups start secreting eCG at day 35 pregnancy
- eCG maintains primary CL and encourdages secondary
- At day 70 eCG falls and cups gone by 150d
- After 200 days- foetal-placental progesterone maintains prengancy
What is the importance of endometrial cups in equine repro?
- Once in place- >35 days can only be removed by natural regression- 150d
- Abbortion must be done <35d if want to breed in same season
How is PD done in horse?
- Failure to return to oestrus: 14-21d
- Lab- eCG from 45-90
- Manual palp- 40d
- Rectal- >14 days, 26d
What are the common causes of pregnancy failure?
- Early loss <40d (10-14 highest)
- Viral- EHV (most common), EVA
- Bacterial- ascending infection
- Fungal- rare
- Twins- opposite horns issue
- Idiopathic
- Foetal abnormalities
- Systemic illness- pyrexia
