Equine Reproduction Flashcards
In the mare a measurement of….. in mammary secretions can aid prediction of foaling…
Calcium carbonate
If calcium carbonate is >200ppm in mares milk what does this indicate?
That the mare will foal in the next 72 hours
50% in the next 24hrs
What type of oestrus does the mare have?
Seasonal polyoestrus - long day breeder
In the horse, the start of the oestrus cyclical activity at the start of the breeding season is most important controlled by?
Daylight length - which is measured by melatonin and the pineal gland
How can you advance the onset of cyclic oestrus in the horse?
Artificial lighting applied during late anoestrus can advance the onset of cyclic oestrus by at atleast 2 months
What are the basic hormonal changes associated with the onset of the oestrus cycle in the mare?
- Daylight length stimulates pulsatile hypothalamic secretions of GnRH
- Resulting in secretion of FSH and LH by pituitary
- FSH stimulates the intital development of ovarian follicles which produce the hormones oestrogen and inhibin
When is melatonin secreted?
During hours of darkness
What is the action of melatonin on GnRH
Inhibitory
In the horse, which vertebrae do the ovaries lay underneath?
L4 and L5
Well-nourished fillies born in the spring may reach puberty at? Where as those born in autumn do not usually reach puberty until?
12 months of age
14-17 months of age
What is the stallions penis classified as?
Haemodynamic
Musclocavernous
What bacterial infectious agents are an issue in horse reproductiin?
Tayorella equigenitalis (CEMO) Klebsiella penumoniae Psuedomonas aeruginosa
What viral infections are an issue in horse reproduction?
EVA
EHV 1 & 3
EIA
How does the mare react to the stallion in oestrus?
Acceptance of the stallion
When is the breeding season of the mare?
Later spring and summer
What produces inhibin?
Ovarian follicles
What hormone is responsible for oestrus behaviour and characteristic cyclic changes in the repro tract?
Oestrogens
What hormone is responsible for dioestrus behaviour?
Progesterone
At approximately 14 days after ovulation, if the uterus recognises that it does not contain a conceptus, endometrial glands produce the hormone…
Prostaglandin
What does the perineum include?
Anus, vulva and adjacent skin
The typical oestrus cycle in a horse last about 21 days
… days of oestrus
… days of dioestrus
5 days of oestrus
16 days of dioestrus
What does the stallion do in the presence of a mare in heat?
Rise to his full height
Arches his neck and prances
Often stretches his neck in the air
Culing his upper lip - Flehman response
Where does fertilisation in the mare occur?
Proximal end of the fallopian tube
In the horse the fertilsed ovum arrives in the uterus about … days after ovulation
5 days
In the horse the yolk sac is small and functions only in the first …. days
20
By about day …. in the horse, the allantoise beings to form
21
What hormone do endometrial cups form in the horse?
Equine chrionic gonadotrophin
eCG
What releases eCG?
Endometrial cups
What time of day are the majority of foals born?
At night
What are the first few signs of approaching labour in the horse?
Enlargement of the udder
Production of waxy secretions at the tips of the teats ‘waxing up’
Relaxation of the pelvic ligaments
What bacterial infections does the HBLB codes of practice give advice on?
Taylorella equigenitalis (CEM) Klebsiella penumoniae Psuedomonas aeruginosa Strangles
What viral infections does the HBLB code of practice give advice on?
Equine viral arteritis (EVA)
Equine herpesvirus-1 (EHV1)
Equine infectious anaemia (EIA)
Equine coital exanthema (EHV3)
What parasitic infections does HBLB code of practice give advice on?
Trypanosomosis - Dourine
What samples do you take from a stallion to test for reproductive bacterial infections?
2 sets of: Urethral smegma Urthreal fossa smegma Prepucial smegma Pre-ejaculatory fluid swabs
What samples would you take to test for EVA?
Serum sample
What sample would you take to test for EIA?
Serum sample
When do you pre-season screen mares and stallion?
After 1st January and before 15th February
What swabs for pre-season screening must you take for mares?
Endometrial swab
Clitoral sinus swab
Clitoral fossa swab
Additional clitoral swab for mares with dystocia to rule out Pseudomonas and Klebsiella
Describe the cervix of a mare in oestrus…
Cervix relaxed, pink and moist
Describe the cervix of a mare in dioestrus…
Tight, pale and dry
What will you see in an US scan of an anovulatory follicle in a mare?
It may be full of fibrin tags
What signs does the mare show if she is in oestrus?
Stands to be mounted Seeks stallions attention Squats Raises tail Rhythmically everts the clitoris Urinates
How long does oestrus usually last in the mare?
5-7 days
In the mare, that is the uterus like when she is in oestrus?
Oedematous and flaccid
How long does dioestrus usually last in the mare?
14-15days
What organism can the clitoris of a mare harbour?
Taylorella equigenitalis (CEM)
What can cause enlarged ovaries in the mare?
Ovarian neoplasia
Haematoma
Anovulatory follicle
What can cause pneumovagina in the mare?
Poor vulvar and perineal conformation
Ovulation in the mare occurs through?
The ovulation fossa
Signs of behaviour oestrus in the mare ceases how many days after ovulation?
1-2days
In the mare how long is the embryo mobile in the uterus? And why is this thought to occur?
Until day 16 after ovulation
It may be necessary for maternal recognition of pregnancy because the maternal embryo inhibits PGF2alpha release
How can you diagnose pregnancy in the horse?
Palpation per rectum Tranrectal US Transabdominal US Oestrone sulphate eCG
When can you use transabdominal US to diangose pregnancy in the mare?
day 80 - term
What produces oestrone sulphate in the pregnant mare?
Foetal gonads
What is a disadvantages of using eCG to diagnose pregnancy in the mare?
Indicates endometrial cups not foetus - false postivies
When can eCG be first detected in the pregnant mare?
day 40
When can you use transrectal US to diagnose pregnancy in the mare?
Day 10 - term
When can you use oestrone sulphate to diagnose pregnancy in the mare?
Day 90
What bacterial infections can cause abortion in the mare?
Strep spp. E. coli Pseudomonas Klebsiella spp. Staphs
What viral infections can cause abortion in the mare?
EHV1
EVA
EIA
What are the non-infectious causes of abortion in the mare?
Twinning Umbilical cord abnormalities Placental insufficiency Uterine body pregnancy Luteal insufficiency
What is ‘waxing up’?
Close to full term (340d) the mars udder enlarges as it fills with colostrum and develops a waxy secretions at the tips of her teats
What are the signs of the 1st stage of labour in the mare?
Restlessness and nest making (digging)
As it progress she shows colic signs and frequently passes small amounts of urine and droppings
Eventually she will lie down look at her flanks as uterine contractions increase abdominal pain
What is the sign that the first stage of labour has ended and the second stage has begun?
Rupture of the first water bag - chorioallantois
When and on what horses would you perform an episiotomy (cutting the vulva and perineal area)?
After the water wag has broken on mares who have had Caslicks surgery previously
- Generally TB broodmares
Caslicks sugery is closure of the upper part of the vulva to prevent pneumovagina
What is red bad delivery?
Premature separation of the placenta prior or during a mare’s foaling
What signifies the beginning of stage 3 labour in the mare?
Expulsion of the foetus
How long should stage 1 labour last in the mare?
Minutes to about 5 hours or longer
How long should stage 2 of labour in the mare last?
15-30mins
How long should stage 3 of labour in the mare last?
Less than 2-3 hours
What are the risk with a prolonged stage 2 of labour for the foal?
Increased risk of hypoxaemia during the birth process.
Any period during labour of hypoxia will predispose the foal to?
Perinatal asphyxia syndrome (PAS) or dummy foal
What could an abnormally long stage 3 labour indicate in for the foal?
Indicates that the placenta is abnormal e.g. infectious placentitis
What is the normal length of gestation for a horse?
320-365days
How long should it take for a foal to stand after birth?
30mins - 1.5hours
How long should it take for a foal to sit in sternal position after birth?
1-5mins
How long after birth should a foal have nursed for the first time?
1h - 2h
What conditions of the pregnant mare can have a significant impact on the foals development in utero?
Bacterial placentitis Placental insufficiency Placental separation Body wall rupture Hydroallantois Uterine torsion Colic Systemic disease Starvation
If a foals development is very slow and they struggle to find the teats, what can this indicate?
PAS or sepsis
Newborn foals have a HR of?
80-100bpm
What is the normal RR of a newborn foal?
60-80/min
Normal temperature of a foal?
37.7-38.8
What are the two main diagnosis for a newborn foal which is quiet and small?
PAS
Sepsis
What are the clinical sign of sepsis in a foal?
Depression, weakness and decreased sucking
Fever, hypothermia or normothermia may be present
Localised signs of infection may be present: uveitis, pneumonia, enteritis, meningitis, septic arthritis
Severe CV collpase
What are the clinical signs of a foal with perinatal asphyxia syndrome?
Mild depression Seizures Organ failure Disorientation Loss of suckle Tongue protusion
What is a premature foal?
Less than 320 days gestation
What is a dysmature foal?
Signs of prematurity in a foal with more than 320 days gestation
What are the signs that can indicate prematurity in foals?
Small Soft/silky coat Floppy ears Increased ROM in joints Weakness Poor thermoregulation Increased chest wall compliance Incomplete ossification of tarsal and carpus bones Respiratory distress due to surfactant deficiency
What test should you do if you suspect a foal is septic?
CBC and acute phase proteins
(fibrinogen, serum amyloid A)
A blood culture could document bacteraemia and confirm sepsis but would take >48hrs
Plasma IgG concentration should be measured to determine the degree of FPT
How would you treat a foal with sepsis?
Antibiotic therapy Immunoglobulin therapy Supportive care - Regulate environment temp - Nutritional support
How would you treat a foal with perinatal asphyxia?
Squeeze the foal Supportive care Seizure control Prevent further brain injury - Osmotic agents - Magnesium sulphate Respiratory support Antimicrobial drugs
What do you check is present when looking at the placenta from the mare?
Tips of both horns
Cervical pole
Amnion
Umbilical cord
What is the cervical star?
An area of fibrosis where the placenta did not attach to the uterus during pregnancy and is the area that the foal breaks through at birth
What do you need to do with the foal on day 1?
Physical exam
Tetanus antitoxin
TMPS
What do you need to do with a foal on day 2?
Physical exam
TMPS
Blood samples for haematology, inflammatory proteins and IgG
What do you need to do with the foal on day 3?
Physical exam
TMPS
When does uterine torsion tend to occur in the horse?
Around 9 months
In the mare, how does uterine torsion tend to present?
Colic
How is streptococcus zooepidemicus most likely to enter a foetus in a mare?
Ascending infections - as bacterial infection in horses are predominantly ascending
Why might systemic illness in the mare comprise foetal development?
May interfere with foetal nutrition and oxygenation
What do precocious lactation in the mare suggest?
Placentitis
Twinning
What is the problem with precocious lactation in the mare?
It places the foal at risk of failure of passive transfer
What normal foal behaviours should you check have occured?
Time to sit sternal (15mins) Time to stand (1-2hours) Time to nurse (2-3hours) Passage of meconium (first few hours) Urination (within 12 hours)
How do foals tend to sleep?
In lateral recumbency
Normal temperature of a foal?
37.2 - 38.6
What is the normal HR within several hours of birth in a foal?
70-100bpm
What is the normal RR for a foal?
20-40/min
What might slow development in a foal indicate? i.e. trouble getting up and finding the teats
Weakness due to sepsis or PAS
Orthopaedic issues
What are the clinical signs of perinatal asphyxia syndrome (PAS)?
CNS: hyperreactivity and then progress to depression and seizures
Resp: tachypnoea and dyspnoea
CVS: tachycardia, hypotension, murmus
Renal: oliguria
GITL ileus, colic, diarrhoea
What are the two main causes of PAS in foals?
Prolonged stage 2 labours
Placentitis - as functional abnormalities can compromised optimal oxygen delivery to foals
What is the CNS form of perinatal asphyxia syndrome known as?
Neonatal encephalopathy (NE)
Common bacterial causes of sepsis in the foal?
E. coli!! Salmonella Klebsiella Staphs Streps Clostridum
What would haemtology show in a foal with sepsis?
Leucopenia
Increased band neutrophils
Increased acute phase proteins
Treatment of sepsis in foals?
Broad spec ABs e.g. cephalosporins/pen + gent
Plasma - for IgG boost
Methods of testing mare colostrum?
Zinc sulphate turbity test
ELISA
Agar gel immunodiffusion
Glutaraldhyde precipitation
Treatment of FPT in foals?
If foal is <18-24 hrs
- Colostrum can be given
- Oral IgG supplement
If foals is 24> hours
- Plasma transfusion
A normal equine placenta should not weigh more than …% of the foals body weight. Increases are likely due to…
11%
Oedema due to infectious causes or toxin insults
