Equine reproduction/neonatology

Question 1

what is a mare?

Answer 1

female horse over 4 years old

Question 2

what is a filly?

Answer 2

female horse young than 4 years old

Question 3

what type of breeder is the mare?

Answer 3

long day, polyoestrus

Question 4

how long is the oestrus cycle of a mare?

Answer 4

21 days

Question 5

how long is diestrus in the mare?

Answer 5

17 days

Question 6

how long does oestrus last in the mare?

Answer 6

4-6 days

Question 7

what does the recruited follicle become?

Answer 7

dominant

Question 8

what does the dominant follicle produce?

Answer 8

oestrogen (induces oestrus)

Question 9

how large does the dominant follicle have to be for ovulation?

Answer 9

> 35mm

Question 10

how long after ovulation with oestrus end?

Answer 10

24 hours

Question 11

what does the ovulation site of the dominant follicle become after ovulation?

Answer 11

corpus haemorrhagicum then corpus luteum

Question 12

what does the CL produce?

Answer 12

progesterone

Question 13

how long after ovulation will luteolysis occur?

Answer 13

15 days (prostaglandin from endometrium)

Question 14

what is the transitional period?

Answer 14

change from anoestrus to regular cycling

Question 15

how do the ovaries appear during the transitional period?

Answer 15

multiple small follicle (bunch of grapes)

Question 16

can the mare be bred during the transitional period?

Answer 16

no

Question 17

how can prostaglandins be used to manipulate oestrus?

Answer 17

induce luteolysis (oestrus commences 3-5 days later)

Question 18

how can progestogens be used to manipulate oestrus?

Answer 18

suppress oestrus, withdrawal leads to rebound ovarian activity

Question 19

what are oestrogens used for?

Answer 19

induce behavioural oestrus (teaser mare)

Question 20

what can chorionic gonadotropin be used for?

Answer 20

stimulate ovulation from dominant follicle within 24 hours

Question 21

what can deslorelin (GnRH) be used for?

Answer 21

induce ovulation in follicle >30mm within 48 hours

Question 22

what is a non-hormonal way of manipulating oestrus?

Answer 22

photoperiod - 16 hours of light from 2-4 weeks before winter solstice

Question 23

how can oestrus be suppressed in the mare?

Answer 23

long term progestogens
intra-uterine device
anti-GnRH vaccine
induce long term CL (oxytocin)
put in foal (then terminate)

Question 24

when should the mare be mated in relation to ovulation?

Answer 24

24-48 hours prior

Question 25

how long is the unfertilised oocyte viable for?

Answer 25

12 hours

Question 26

how long is spermatozoa viable for?

Answer 26

48 hours in mares reproductive tract

Question 27

what are the features found when scanning a mare in oestrus?

Answer 27

dominant follicle uterine oedema soft oedematous cervix (behavioural signs)

Question 28

how does a dominant follicle appear just before ovulation/

Answer 28

softens and pointing to ovulation fossa

Question 29

how does the oedema of the uterus appear just before ovulation?

Answer 29

cartwheel oedema begins receding 24 hours prior

Question 30

how long after mating should a mare be scanned?

Answer 30

12-24 hours (check for ovulation)

Question 31

what are the important mechanisms of perineal conformation?

Answer 31

vulva seal vestibular seal cervical competence

Question 32

why is perineal conformation important?

Answer 32

poor confirmation leads to pneumovagina causing urovagina and leading to bacterial contamination

Question 33

what is done during a caslicks vulvoplasty?

Answer 33

suture vulva lips together as much as necessary (for poor perineal conformation)

Question 34

what problem can persistant CL cause?

Answer 34

no oestrus (give prostaglandins)

Question 35

what problem can anovulatory follicles cause?

Answer 35

prolonged oestrus followed by prolonged luteal phase

Question 36

what are the three types of endometritis?

Answer 36

chronic infectious metritis free fluid in lumen mating induced endometritis

Question 37

how long do you have to treat mating induced endometritis?

Answer 37

5 days (conceptus in oviduct for 5 days)

Question 38

what is chronic degenerative endometrial disease?

Answer 38

progressive degeneration of endometrium that is replaced by fibrotic tissue

Question 39

what is the gestation period of a horse?

Answer 39

336 days from mating (rough)

Question 40

where does fertilisation occur?

Answer 40

oviduct

Question 41

what happens once the embryo enters the uterus?

Answer 41

migrates for 15 days

Question 42

what is the migration of the embryo around the uterus essential for?

Answer 42

maternal recognition of pregnancy | prevent prostaglandin release from endometrium

Question 43

when does placental attachment occur?

Answer 43

36 days after mating (base of horn)

Question 44

when does production/attachment of endometrial cups occur?

Answer 44

35 days after mating

Question 45

what maintains pregnancy for the first 5 months?

Answer 45

CL secreting progesterone

Question 46

what is the function of the endometrial cups?

Answer 46

secrete eCG to maintain CL and encourage secondary CL formation

Question 47

when do the endometrial cups begin to degenerate?

Answer 47

day 70 (gone by day 150)

Question 48

what maintains pregnancy once endometrial cups have degenerated and CLs have gone?

Answer 48

foetal placental progesterone

Question 49

what happens to the endometrial cups if the foal dies?

Answer 49

cups remain (no oestrus)

Question 50

how can behavioural signs be used for pregnancy diagnosis?

Answer 50

no oestrus behaviour and won't accept mare 14-21 days after mating

Question 51

when can eCG in blood be used to diagnose pregnancy?

Answer 51

day 45-90

Question 52

when can oestrone sulphate in blood be used to diagnose pregnancy?

Answer 52

day 120 onwards (also indicated foetal viability)

Question 53

how far into pregnancy usually used?

Answer 53

day 40

Question 54

how large will the lump be at day 40 in gestation?

Answer 54

grapefruit

Question 55

when is the best time to ultrasound scan for pregnancy diagnosis of the mare?

Answer 55

first scan 15-16 days | second scan 24-26 days

Question 56

why is a pregnancy scan done 15-16 days after mating?

Answer 56

check for twins and pregnancy

Question 57

why is a pregnancy scan done 24-26 days after mating?

Answer 57

heartbeat visible | can still terminate before endometrial cups

Question 58

how far into the pregnancy can trans abdominal scanning be used to confirm pregnancy?

Answer 58

6 months

Question 59

when does early embryonic death occur?

Answer 59

before day 40

Question 60

what can cause early embryonic death?

Answer 60

congenital abnormalities uterine infection/environment breeding on foal heat

Question 61

what is foal heat?

Answer 61

the first heat roughly 7 days after the mare has foaled

Question 62

what are possible viral infections that can cause abortion?

Answer 62

equine herpesvirus 1 equine viral arteritis bacterial (ascending infection, haematogenous) fungus

Question 63

how can abortion due to equine herpesvirus 1 be prevented?

Answer 63

vaccinate 5, 7, 9 months into pregnancy

Question 64

what is done if a twin pregnancy is diagnosed?

Answer 64

abort | one twin manually crushed

Question 65

how can abortion be induced before 3 months?

Answer 65

prostaglandin

Question 66

how can abortion be induced after 3 months?

Answer 66

repeated prostaglandin | dilate cervix

Question 67

how can foaling be induced?

Answer 67

oxytocin injection (large risk for dystocia/rupture)

Question 68

what is prematurity?

Answer 68

foal born at a gestational age of <320 days with immature physical characteristics

Question 69

what is dysmaturity?

Answer 69

full term foal with immature physical features

Question 70

what are the characteristics of a premature/dysmature foal?

Answer 70

``` low birth rate short silky hair floppy ears domed head flexor tendon laxity incomplete ossification ```

Question 71

when does maximum absorption of colostrum occur in foals?

Answer 71

within 8 hours of life

Question 72

what are predisposing factors for the failure of passive transfer of immunity (colostrum)?

Answer 72

premature lactation (colostrum loss) inadequate colostrum production failure to ingest/absorb

Question 73

when does IgG peak?

Answer 73

18 hours

Question 74

what is given to treat failure of passive transfer over 12 hours of age?

Answer 74

plasma transfusion

Question 75

what are the risk factors for neonatal illness?

Answer 75

``` dam health during gestation gestational/foaling environment ease of delivery gestational age at birth placental abnormalities placental transfer of immunoglobulins ```

Question 76

how long should it take the suckling reflex to be present in foals?

Answer 76

within 20 minutes

Question 77

how fasts should meconium be passed?

Answer 77

within 24 hours

Question 78

what is the body temperature of a neonatal foal?

Answer 78

37.2-38.9 (higher than adult)

Question 79

what is the heart rate of a neonatal foal?

Answer 79

40-80bpm

Question 80

how do the normal lungs of neonatal foals sound?

Answer 80

harsh/loud

Question 81

what is the first and most important differential of a sick neonatal foal?

Answer 81

neonatal septicaemia

Question 82

what are the risk factors for neonatal septicaemia?

Answer 82

failure of passive transfer | hygiene, stress, disease, management

Question 83

what are common pathogens causing neonatal septicaemia?

Answer 83

``` E. coli Actinobacillus Salmonella Streptococcus Staphylococcus (mixed) ```

Question 84

how can organisms enter the foal to cause neonatal septicaemia?

Answer 84

openings (umbilicus) open gut inhalation un utero

Question 85

what are the clinical signs neonatal septicaemia?

Answer 85

``` off-suck and lethargy increased respiratory rate/effort dark MM petechial haemorrhage diarrhoea hypopyon meningitis lameness (swelling) ```

Question 86

what happens during septic shock?

Answer 86

vasodilation increased metabolic rate and oxygen consumption initial increase of CO