Reproduction Flashcards
Mare - itchy vulva - coital exanthama
EHV-2 - coital exanthama
Multiple erosive, crusted lesions
Cease breeding until lesions have resolved
Isolate mare
From stallion and environment - contaminate management
No abortion, infertility or foetal abnormalities - stallion sore penis
Diagnostic approach to any mare - breeding specific
History
Specific details
History
* Previous fertility
* Consider venereal pathogens
* General clinical examination
* Mammary
* Perineum
* Vulva, vestibule, vagina, cervix
* Uterine palpation and ultrasound
* Ovarian palpation and ultrasound
Relating to the History
Current Presentation
* Pregnant
* With a foal at foot
* Barren (in equine terms meaning bred last year but did not get pregnant)
* With a specific problem
Really important questions are:
* Age
Previous breeding history
* Not pregnant
* Early pregnancy loss
* Abortion / stillbirth
If barren
* What was the management last year?
* Who was the Vet last year?
* Number of years barren?
Specific Details
General physical examination
* Body condition
* General observations
* Feet
* Udder
Perineum
* Long axis of the vulval should be vertical
* Vulvar labia should be well apposed
* No vulval discharge
* No vulval lesions
* Perineum should be intact
* Anus should not be recessed
* Normal vestibulo-vaginal seal
* Need to part vulval lips to establish this
HBLB Codes of Practice
* Venereal transmitted bacterial diseases caused by the contagious equine
metritis organism CEMO, Klebsiella pneumoniae and Pseudomonas
aeruginosa
* Equine Viral Arteritis - EVA
* Equine Herpesvirus - EHV
* Equine Coital Exanthema - ECE
* Equine Infectious Anaemia - EIA
* Dourine
* Strangles
* Artificial Insemination – AI
Bacterial venereal pathogens
HBLB: specific guidelines each year for specific categories of mare (walk in, resident etc) for:
* Taylorella equigenitalia (Contagious equine metritis organism [CEMO])
* Klebsiella pneumoniae (Capsule types 1,2,5)
* Pseudomonas aeruginosa (specific strains but not possible to type these in routine testing so all are therefore [incorrectly] assumed to be pathogenic)
These define number of swabs, where from and how may repeats
- Remember:
- You need to swab the fossa and sinus (and in some cases the uterus)
- You need Amies transport media
- You need to send to Approved Lab
- Culture needs to commence within 48h
Certificate will only state whether isolated or not
Sometimes will say what Klebsiella capsule type was - 1,2,5 are pathogenic
No designation for pseudomonas strain
You may breed a Klebsiella positive depending on capsule type
May also breed positive Pseudomonas if sure this is not venereal pathogen
What to do if CEM (Taylorella equigenitalis) is isolated
In mares prior to covering - isolate and treat infected mares, notify owner of mare
Stallions prior to covering - isolate nad treat, notify owner of stallion
Mares and stallions post covering - cease covering, check all mares, do not cover until 3 negative swabs at least 2 days apart
Viral venereal pathogens
Viral Venereal Pathogens
* Normally ensure mare is serologically negative to Equine Viral Arteritis (or vaccinated for this)
N.B. EVA is notifiable by law in the UK
Equine viral arteritis
* Transmitted both via respiratory tract route and also venereally (including chilled semen)
* Classic disease is flu-like but with significant conjunctivitis, (pink eye) focal dermatitis, limb and ventral oedema
* Organism excreted at this time and in the stallion may infect the accessory glands and result in a persistent infection (mares clear infection within 1 month and develop immunity)
* Pregnant mares that get infected may abort (abortion may relate to degree of immunity or pathogenicity of virus strain)
* Aborted fetuses appear partialy autolysed (unlike fresh fetuses in EHV) however still need appropriate pathological examination
Vaccination planned for Equine Herpes Virus 1 (planned for month 5, 7 and 9 of
pregnancy e.g. Equip EHV 1,4) - common cause of abortion and neurological
* Inspection negative for signs of Equine Herpes Virus 3 (Equine coital exanthema)
* Serologically negative for Equine infectious anaemia (EIA) for horses returning to UK
N.B. EIA is notifiable in the UK
* Quarantine on entry to stud to demonstrate no signs of Strep Equi (Strangles) develop
Why take uterine swabs?
For bacterial venereal pathogen screening
In cases of endometritis - endometrial cytology, C&S, other pathogens
Strict aseptis required
Always ensure not pregnant before breeching cervix
Guarded swab
Single swab rolled onto sterile, clean microscope for staining for cytology before placing into charcoal based transport for culture
Often taken during oestrus - can find more organisms in oestrus as open cervix - so may find non-venereal
Vaginal examination
Digital, speculum, endoscopic of vagina and cervix
Confirm normality and estimation of stage in cycle
Evidence of gross pathology
* e.g. Presence of persistent hymen
* e.g. Evidence of disease such as vaginitis or cervicitis
* e.g. Evidence of trauma including scaring or deformation of cervix
* e.g. Pooling of urine or pus in the vagina
Rectal examination
Of cervix, uterus, ovaries
* Confirmation of normality
* Confirmation of cyclicity and stage of cycle
* Confirmation of non-pregnancy
* Evidence of gross pathology
* e.g. Absence of, or large uterus
* e.g. Inactive ovaries, or large ovaries
Uterine tone when under progesterone - dioestrus, luteal phase - opposite to cows - in oestrus will have tone in cows
US examination
Of the uterus:
* Confirmation of normality
* Confirmation of cyclicity and stage of cycle
* Confirmation of non-pregnancy
* Evidence of gross pathology
Free fluid in uterus – normal immediately after mating – otherwise never normal
Tomato appearance – uterine oedema – oestrus
Of the ovaries:
* Confirmation of normality (refer to rectal palpation material on previous slides)
* Confirmation of cyclicity and stage of cycle
* Remember follicles are fluid-filled (anechoic), CHs are generally bright white (but may
be cavitated) and CLs are echogenic
* Evidence of gross pathology
Cannot feel CL – once ovulated can feel corpus haemoragicum (day 5 will regress)
What will endometrial cytology tell us
Presence of uterine fluid on ultrasound is abnormal and in GE’s opinion can lead to a diagnosis of endometritis (except when there is significant oedema during oestrus and a small volume of fluid which disappears as the oedema disappears)
- In these cases some veterinarians will take uterine swabs for cytology (presence of neutrophils) and microbiology (rule out venereal pathogens, identify causative pathogen and sensitivity [requires special culture for yeast etc])
- Swabs for CEM are often taken during oestrus, however when not routine screening for CEM we need to consider what importance we should place on finding bacteria within the uterus when the cervix is open?
My preference is to swab during dioestrus when identification of any bacteria (as long as technique is sterile) is always significant.
Always administer PG after swabbing: the ensures the mare returns to oestrus and usually microbiology results are back at an appropriate time - Strict asepsis, technique as before and staining with common to use
Diff Quik staining - Identify presence of endometrial cells (to show suitable sample), and
then evaluate the number of neutrophils per medium power field
(x400 = x40 lens and x10 eyepiece) - Some neutrophils is normal
- More than 5 neutrophils per MPF is classified as abnormal
- May also identify pathogens in some cases
Endometrial bacteriology
Endometrial Bacteriology
* Aerobic culture
* Microaerophilic culture
* Anaerobic pathogens
* Yeast / fungi
The most common pathogen is Streptococcus zooepidemicus
(aerobic culture)
Identifying organisms means uterine infusion not systemic treatment (essentially this is
uterine contamination)
What antibiotic preparations are licensed for uterine influsion and which are you going to
use?
When to endometrial biopsy
Barren mares
Repeat breeder mares
Mares with early embryonic death or abortion
Anoestrus mares - during breeding season
Mares requiring surgery of genitial tract
Pyometra or mucometra
Fertility evaluation - prepurchase
Technique
* Restrain mare, bandage tail, strict asepsis
* Manually dilate cervix then pass sterile basket-jawed forceps into the uterine lumen
* Position forceps so that cutting jaw faces dorsally: open the jaws push onto endometrium, close the jaws and give a ‘tug’ (may need to be forceful)
* It is virtually impossible to rupture the uterus
* Haemorrhage is rarely significant
* The mare is not aware of the procedure
* Sample put into adequate volume of Bouin’s fluid
Useful for diagnostic aid and some
aspect of prognosis
* Pathological changes include:
* Acute inflammation
* Neutrophil and occasionally eosinophil
infiltration
* Chronic infiltrative inflammation (repeated
bouts of acute inflammation)
* Mononuclear cells
* Chronic degenerative changes
* Layers of fibrous tissue around dilated glands
* May also get dilated lymphatics (ageing)
Endometrial Biopsy
A classification has been developed for EB, and although it is not universally used it demonstrates
principles relating to prognosis:
- Category I
- No pathological changes and mare should have normal fertility
- Estimated foaling rate = 80-90%
- Category IIA
- Mild endometrial changes
- 50 to 70% of these mares will foal
- Category IIB
- Moderate endometrial changes
- Inflammatory changes severe enough to decrease fertility and may be accompanied by fibrosis
- 20 to 50% of these mares will foal
- Category III
- Severe endometrial changes
- Uteri may be incapable of supporting fetal development
- Estimated foaling rate = <10%
Uterine endoscopy
Uterine Endoscopy
* First ensure the mare is not pregnant
* Following strict asepsis placement of flexible endoscope
into vagina and through the cervix
* Direct visualisation and detection of congenital or
acquired abnormalities
* Cutting or diathermy may be useful for management of
some clinical conditions
Mare - karyotyping
Most likely to be used following
* Clinical suspicion of problem eg:
* Clitoral enlargement
* Infantile vulva and vagina
* Small uterus
* Small inactive ovaries
* In mare that should have reached puberty and is not within the winter anoestrus period
* Remember mares just out of training may not be cycling
* Normal is 64XX
* Spontaneous aneuploidy is an occasional cause of infertility
* One of the common abnormalities is 63XO a condition referred to a Turner’s Syndrome
* Tubulogenital tract normal but small, ovaries very small and inactive
* Surprisingly may show irregular non-cyclical oestrous behaviour
* Other abnormalities include 62XX and XXY
Reproductive biology in the mare
Reproductive Biology in the Mare
* Seasonally polyoestrus
* Normal breeding May to October
* Early spring: mares have transitional period with follicles that don’t ovulate (ovaries can be very large – 2 large ovaries)
* Late autumn: cyclicity ends with silent or anovulatory heat (some pones cycle throught winter)
* But, the required breeding season is mid-Feb to July because registered birthdate is 1st
January
TB mares not normally cycling in February (photoperiod) but are required to foal early in
the year because of January 1st registration date
* Mare likely in anoestrus (suppression by melatonin) but enters transitional period
* Signs of transitional period
* Mare has follicles that grow and regress (either not enough LH or LH-receptors) but don’t ovulate
* Ovaries may be large, follicles may be detected
* Oestrous behaviour is usually present
* Mare may stand to be bred
* However does not ovulate and oestrous behaviour may be present weeks later
* This is normal and the mare will ultimately ovulate
* Some mare owners continue to serve whilst mare stands (may be served every other day for weeks)
* The follicle that ovulates may be difficult to predict so sometimes despite best efforts everyone is fed-up and the mare does not get bred at the correct time
- Since the required breeding season starts on approximately 15th February
the best plan is to enhance the onset of the transitional period and then to
attempt to shorten the transitional period - This is done by:
- Providing 16hrs artificial light and additional nutrition from 1st December
- Some clinicians also administer GnRH agonists at this time but efficacy is unproven
- Once the mare is within the transitional period (follicles greater than 2.5 cm in diameter) progestogens are administered to suppress the release of LH
*
Normally Altrenogest - a progestin (Regumate) is given in feed for approximately 10 days - Follicles continue to grow during progestogen treatment
- When follicles reach 4.5 cm progestogen treatment is stopped and there is a surge release of LH which induces ovulation
- Some clinicians also administer GnRH at this time to enhance the LH release
