HORSE REPRODUCTION Flashcards
Increasing daylength stimulates pulsatile hypothalamic secretion of _____
Gonadotrophic releasing hormone which in turn results in secretion of FSH and LH from the anterior pituatary gland
If the horse uterus does not contain a conceptus, at what day is prostaglandin produced?
Day 14 reaches ovaries via the blood.
During oestrous muscular wall of uterus is flaccid.
The cervix is dilated, oedematous, moist and red in oestrus
When does the pineal gland produce melatonin?
During hours of darkness. Therefore long day breeder (horse) means melatonin inhibits GnRH
In the horse, what is the average size for a follicle to ovulate?
4cm i.e. when the walls become thin.
Mature follicle bursts at the ovulation fossa, discharging contents towards fallopian tube
Where does fertilisation happen in the horse?
In the oviducts (fallopian tubes) allows for uterine washing.
Fetilised ovum returns to uterus after 5 days
How does the season in which a fillie was born affect when it reaches puberty?
Born in spring= 12 months
Born in autumn= 14-17months (two springs later)
Average age of puberty in stallion
14 months. Seasonal breeders. Maximal function May, June, July
What type of placenta does the horse have?
Diffuse (remember the movement around the uterus), epitheliochorial
At what age does equine chorionic gonadotrophin start to be secreted and b) stop being secreted?
a) Starts being secreted from endometrial cups at day 40
b) Stops around day 90
What day does maternal recognition of pregnancy occur in the horse?
Day 14
The end of first stage labour, in the horse is signified by the rupture of the first water bag i.e. the ______
Chorioallantois
The rupture of the chorioallantois (end of first stage labour) in horse can be differentiated from urination in what two ways?
- Not normal urinating stance when ruptured
2. Voluminous quantity (mare has already passed small quantities or urine regularly in first stage)
What is ‘waxing-up’ indicative of?
‘waxing-up’ is the production of a waxy secretion at the tips of the teats. Relaxation of the pelvic ligaments frequent small volume urination, sweating, standing up and down all signs of stage one. Ends by rupture of chorioallantois. Should last <4hrs
Why following expulsion of the foal, do the hindlegs sometimes remain in the vagina; as if the mare is exhausted?
Allows for transfer for placental blood. DO NOT RUPTURE THE UMBILICAL CORD FOR 5 MINUTES
What happens to the foals respiratory rate following birth?
Respiratory movements should start within 30 seconds of birth. Respiratory rate then declines from 75/MIN TO 34bpm after 12 hours (as increasing blood oxygen levels)
Newborn foal heart rate? Ausculating the new born foal may reveal a ….
40-80bpm. Increases when standing.
Patent ductus venosus causes a loud systolic murmer which is considered NORMAL
Normal heart rate for asphyxiated foal
Bradycardia (140bpm)
Newborn foal temperature after 1 hr
When born= 37
After one hour =38
Approximate timings for foal to:
1) Sternal recumbancy
2) Standing
3) Suckle
1) Raise head and sternal recumbancy after 5 minutes
2) Standing within 2 hours otherwise abnormal
3) Suckle mean time is 111minutes
A foal that following suckling does not sleep may be indicative of…
The mare not letting the milk down i.e. foal is still hungary; should drink then sleep.
Excessive sneezing/coughing when suckling could be indicative of a cleft palate
Significance of meconium in the new born foal
Passed before birth = distress and urgent examination required.
Passed within 24 hrs = normal
Should be passed within 4 days OTHERWISE examination; normally associated with signs of colic
Significance of Coprophagia in new born foals
Inquisitive behaviour normally by 2 days of birth.
Coprogphagia of mothers faeces is normal and could be to populate foals intestinal tract
Significance of foal diarhorea
Mare normally shows first oestrous 7 daus post partum. Followed by 1-3 days of foal diarrhoea
When does weaning of foals on stud farms occur
5-6 months of age
Testes plus female external genitalia is known as
Male pseudohermaphroditism
Ejection of stallion semen is controlled by what nerves
Sympathetic stimuli mediated by pudendal nerve and sacral segment of the spinal cord
How long after pyrexia in the stallion is the reduction in sperm concentration noticed?
4-6 weeks after pyrexia
Which three bacterias can spread venerally and cause endometritis within groups of previously healthy mares?
Taylorella equigenitalis, Klebsiella pneumoniae, (capsule 1,2,5) Pseudomonas aeruginosa.
Can proliferate on the genital skin, stallion rarely shows clinical signs but acts as mechanical transmitter to mares
WHEN and WHERE should swabs be taken for thee three bacterial pathogens that can be mechanically spread by the stallion?
Two swabs, no less than 7 days apart after 1-jan before start of mating season.
- Urethra
- Urethral fossa
- Prepuce
- Pre-ejaculatory fluid
Treatment of Taylorella equigenitalis in stallion
Two strains - streptomycin resistant and streptomycin sensitive.
Treat stallion daily for 5 days by erection and washing penis and prepuce with clorhexidine surgical scrub (2%)
Repopulate with broth culture
Treatment of Klebsiella pneumoniae
Only K.Pneumoniae types 1, 2 and 5 have clinically demonstrated potential.
Wash penis and prepuce with non-antiseptic soap and water to remove smegma, Was with aqeuous 1% hypochlorite and apply gentamicin
Repopulate with broth
Treatment of Pseudomonas aeruginona
NO ASSOCIATION HAS BEEN PROVEN but NO CHOICE but to TREAT.
Treated for 10 days non-antiseptic soap and water, then sprayed with 1% silver nitrate
Repopulate with broth
What are the viral infections that affect the breeding stallion?
- Equine Herpesvirus-3 (coital exanthema)
- Equine Viral Arteritis
Protozoal infection that affects breeding stallions. Main DDx of this?
Trypanosoma equiperdum causes DOURINE IN HORSES.
NOTIFIABLE HORSES IN UK
Pyrexia, Anorexia, Oedema of genitalia, characteristic raised urtercarial skin (THEREFORE DIFFERENTIAL DIAGNOSIS OF EHV-3)
A stallion has small vesicles on penis and prepuce. What could be the responsible pathogens ?
Equine herpes virus-3 (coital exanthema) Trypanosoma equiperdum (dourine) urticarial skin
How is Equine Viral Arteritis spread? What is the common presentation
Respiratory and Venereal infection. Nasopharangeal swap.
Pyrexia, Conjuctivitis, serous nasal discharge, limb /scrotal oedema
Why is the Caslick’s procedure done?
To prevent pneumovagina
When mare ages the anus sinks cranially causing the vulve to slope cranially to caudally.
WANT CAUDAL to CRANIAL to PREVENT Pneumovagina
Which pathogen causes Contagious Equine Metritis (CEM)?
notifiable Taylorella equigenitalis. Use 2% clorhexidine as treatment
Eradicated from UK
