HORSE REPRODUCTION

Question 1

Increasing daylength stimulates pulsatile hypothalamic secretion of _____

Answer 1

Gonadotrophic releasing hormone which in turn results in secretion of FSH and LH from the anterior pituatary gland

Question 2

If the horse uterus does not contain a conceptus, at what day is prostaglandin produced?

Answer 2

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

Question 3

When does the pineal gland produce melatonin?

Answer 3

During hours of darkness. Therefore long day breeder (horse) means melatonin inhibits GnRH

Question 4

In the horse, what is the average size for a follicle to ovulate?

Answer 4

4cm i.e. when the walls become thin.

Mature follicle bursts at the ovulation fossa, discharging contents towards fallopian tube

Question 5

Where does fertilisation happen in the horse?

Answer 5

In the oviducts (fallopian tubes) allows for uterine washing.
Fetilised ovum returns to uterus after 5 days

Question 6

How does the season in which a fillie was born affect when it reaches puberty?

Answer 6

Born in spring= 12 months

Born in autumn= 14-17months (two springs later)

Question 7

Average age of puberty in stallion

Answer 7

14 months. Seasonal breeders. Maximal function May, June, July

Question 8

What type of placenta does the horse have?

Answer 8

Diffuse (remember the movement around the uterus), epitheliochorial

Question 9

At what age does equine chorionic gonadotrophin start to be secreted and b) stop being secreted?

Answer 9

a) Starts being secreted from endometrial cups at day 40

b) Stops around day 90

Question 10

What day does maternal recognition of pregnancy occur in the horse?

Answer 10

Day 14

Question 11

The end of first stage labour, in the horse is signified by the rupture of the first water bag i.e. the ______

Answer 11

Chorioallantois

Question 12

The rupture of the chorioallantois (end of first stage labour) in horse can be differentiated from urination in what two ways?

Answer 12

1. Not normal urinating stance when ruptured

2. Voluminous quantity (mare has already passed small quantities or urine regularly in first stage)

Question 13

What is ‘waxing-up’ indicative of?

Answer 13

‘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

Question 14

Why following expulsion of the foal, do the hindlegs sometimes remain in the vagina; as if the mare is exhausted?

Answer 14

Allows for transfer for placental blood. DO NOT RUPTURE THE UMBILICAL CORD FOR 5 MINUTES

Question 15

What happens to the foals respiratory rate following birth?

Answer 15

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)

Question 16

Newborn foal heart rate? Ausculating the new born foal may reveal a ….

Answer 16

40-80bpm. Increases when standing.

Patent ductus venosus causes a loud systolic murmer which is considered NORMAL

Question 17

Normal heart rate for asphyxiated foal

Answer 17

Bradycardia (140bpm)

Question 18

Newborn foal temperature after 1 hr

Answer 18

When born= 37

After one hour =38

Question 19

Approximate timings for foal to:

1) Sternal recumbancy
2) Standing
3) Suckle

Answer 19

1) Raise head and sternal recumbancy after 5 minutes
2) Standing within 2 hours otherwise abnormal
3) Suckle mean time is 111minutes

Question 20

A foal that following suckling does not sleep may be indicative of…

Answer 20

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

Question 21

Significance of meconium in the new born foal

Answer 21

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

Question 22

Significance of Coprophagia in new born foals

Answer 22

Inquisitive behaviour normally by 2 days of birth.

Coprogphagia of mothers faeces is normal and could be to populate foals intestinal tract

Question 23

Significance of foal diarhorea

Answer 23

Mare normally shows first oestrous 7 daus post partum. Followed by 1-3 days of foal diarrhoea

Question 24

When does weaning of foals on stud farms occur

Answer 24

5-6 months of age

Question 25

Testes plus female external genitalia is known as

Answer 25

Male pseudohermaphroditism

Question 26

Ejection of stallion semen is controlled by what nerves

Answer 26

Sympathetic stimuli mediated by pudendal nerve and sacral segment of the spinal cord

Question 27

How long after pyrexia in the stallion is the reduction in sperm concentration noticed?

Answer 27

4-6 weeks after pyrexia

Question 28

Which three bacterias can spread venerally and cause endometritis within groups of previously healthy mares?

Answer 28

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

Question 29

WHEN and WHERE should swabs be taken for thee three bacterial pathogens that can be mechanically spread by the stallion?

Answer 29

Two swabs, no less than 7 days apart after 1-jan before start of mating season.

• Urethra
• Urethral fossa
• Prepuce
• Pre-ejaculatory fluid

Question 30

Treatment of Taylorella equigenitalis in stallion

Answer 30

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

Question 31

Treatment of Klebsiella pneumoniae

Answer 31

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

Question 32

Treatment of Pseudomonas aeruginona

Answer 32

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

Question 33

What are the viral infections that affect the breeding stallion?

Answer 33

• Equine Herpesvirus-3 (coital exanthema)

- Equine Viral Arteritis

Question 34

Protozoal infection that affects breeding stallions. Main DDx of this?

Answer 34

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)

Question 35

A stallion has small vesicles on penis and prepuce. What could be the responsible pathogens ?

Answer 35

Equine herpes virus-3 (coital exanthema)
Trypanosoma equiperdum (dourine) urticarial skin

Question 36

How is Equine Viral Arteritis spread? What is the common presentation

Answer 36

Respiratory and Venereal infection. Nasopharangeal swap.

Pyrexia, Conjuctivitis, serous nasal discharge, limb /scrotal oedema

Question 37

Why is the Caslick’s procedure done?

Answer 37

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

Question 38

Which pathogen causes Contagious Equine Metritis (CEM)?

Answer 38

notifiable Taylorella equigenitalis. Use 2% clorhexidine as treatment
Eradicated from UK