Equine Repro Flashcards
What areas of the equine repro tract harbor bacteria?
Clitoral fossa
Clitoral sinuses
What is the most sensitive organ to hormonal stimulation in the horse?
Cervix
Describe the cervix under the influence of progesterone
Closed
Dry
Homogenous appearance on ultrasound
Describe the cervix under the influence of estrogen
Low relaxed moist hypertrophic and edematous "cartwheel" shaped n ultrasound
Describe the cervix during midestrus
Moist and on the floor of the vagina
Dorsal frenulum is present
What is different about the cervix of the equine compared to other species?
always dilatable due to the absence of fibrous rings
Describe the Uterus in the mare compared to the cow
Y- or T-shaped ovaries
more lateral than cow
Why are the endometrial folds critical in the equine repro tract?
reproductive management
defense
Where do you find unfertilized ova in the equine?
Oviduct
When do fertilized ova descend into the uterus?
day 5.5
What causes the Uterotubule junction to open?
PGE
What is the function of the oviduct in the equine?
Sperm storage
Fertilization site
embryo transport
What is the hormone for maternal recognition in equine?
Prostaglandin E2
When would you flush the equine for embryo transfer?
day 7-8
What is the size of a mature follicle?
40+ mm
Where do follicles ovulate in the ovary?
ovulation fossa
Why does the follicle change shape when it ovulates?
as the follicle migrates to the ovulation fossa it changes shape from spherical to oblong
How many glands are in each side of the mare’s udder?
2 glands
What is the only pathology of the mare’s udder?
Mastitis
What gland is responsible for the mare’s cyclic breeding?
Pineal gland
What type of breeders are equine?
Long day breeders
Describe how melatonine affects GnRH
High levels of Melatonin in dark days inhibit production of GnRH
Low levels of Melatonin produce GnRH
What happens to Mares during Winter anestrous?
About 30% show heat but only half ovulate
What happens during the Spring Transition in mares?
Begin to display heat but may not ovulate
Describe the uterus in anestrous
no ovarian activity
uterus is flaccid with no tone
When should you start putting the mare under lights to stimulate estrous?
60 days before
How many hours of light do you need to expose the mare to to affect her seasonality?
16 hours of daylight
Describe the Transitional period in mares
Mares have multiple variable size follicles
Uterus has estrual tone, evidence of uterine edema
Displays signs of estrus for variable length of time
Ends with the first ovulation of the year
How can you reduce the length of the Transitional period?
Progesterone Progestagens Dopamine antagonists Domperidone Sulpiride
What would cause a mare to mount another mare?
testosterone secreting pathology
What can you use to induce ovulation?
Human chorionic gonadotropin
Deslorelin injectable
Recombinant LH
What is the problem with hCG?
High antigenicity due to the large molecule size
What is the advantage of using Deslorelin (GnRH)?
Induces more effectively and over a shorter period of time
When does the CL reach maximum maturity level?
day 4-5
What are possible causes of failure to respond to ovulatory inducing agents?
“immature follicles” with not enough LH receptors
Mares are not in estrus even though a large follicle is present
Anovulatory follicles
HAF
Hemorrhagic Anovulatory Follicles
Hemorrhagic Anovulatory Follicles (HAF)
Fails to ovulate in response to ovulatory inducing agents
What are the options for luteolysis and estrus induction?
PGF 2 alpha
Cloprostenol
What is the estrus interval average after luteolysis?
3-5 days
What is the ovulation interval after luteolysis?
8-10 days
Where is PGF 2 alpha metabolized?
in the lungs
What are the side effects of PGF 2 alpha?
Diarrhea
Abdominal cramps
sweating
When is the CL responsive to prostaglandin?
5 days
What are the wrong used of Prostaglandin?
Ovulation induction
Uterine evacuation post-ovulation
Induction of parturition
What determines the interval between prostaglandin injection and ovulation?
Size of the follicle at the time of treatment
What are the factors that maximize your chances of a pregnant mare?
Good management
Clean Mare
Good Timing
Good semen
How many days from the time of ovulation to the next time the mare shows heat?
15 days
How often can a stallion breed per day?
2-4 times
What is the limiting factor for number o times a stallion breeds per day?
Libido
Describe Endometrial Edema Grade 4
Thicker Hypo-echoic center Hyper-echoic wall More prominent at the uterine body but still maintains a nice uterine architecture "cart wheel"
Describe Endometrial Edema Grade 5
Hyper-edema
Very thick endometrial folds loss of “normal” US architecture
Increased surface area, often free fluid not observed
Follicles variable
When should you breed pre-ovulation with natural breeding in the mare?
72-48 hours pre ovulation
When should you breed pre-ovulation with Fresh semen in the mare?
less than 48 hours pre ovulation
When should you breed pre-ovulation with fresh cooled semen in the mare?
24-36 hours pre ovulation
When should you breed pre-ovulation with frozen semen in the mare?
less than 12 hours pre ovulation
Why do we not want to inseminate post ovulation in the mare?
DNA damage is very quick once the egg is released
Definition of proper artificial insemination
Deposition of good quality semen into the uterus of a clean mare at the right time
What are the advantages of AI in the mare?
Maximize efficiency of stallion usage
Increase genetic pool due to increased availability of stallions
More regular evaluation of stallion semen
Reduce risk of sexually transmittable diseases
Increases safety of animals and handlers
What is the main factor contributing to sperm migration to the oviduct of the mare?
Uterine contractility
Where are sperm deposited in the mare?
Uterus
What is responsible for eliminating excess fluid from the uterus in the mare?
Myometrial contractions
What is the order of fertility in mares?
- Young Maiden Mare
- Early Foaling Mares
- Barren Mares
- Old Maiden Mares
What type of insemination is used in mares to reduce inflammation and increase pregnancy rates with difficult stallions?
Deep Horn Insemination
What is the order of best treatment options for mares that do not become pregnant when bred with good semen under excellent management conditions?
- Embryo transfer
- Oocyte transfer
- Intracytoplasmic sperm injection
What are the indications for embryo transfer in mares?
Young mares in competition
Mares with severe uterine problems
More than one foal a year
Biopsy for desired outcome (HERDA, HYPP, GEBD, EPSM, Gender)
Indications for Cytoplasmic Sperm injection
Old mares where it is not possible to retrieve an embryo
Oviductal disease
Mares that have died
Use of stallions with very limited amount of semen available
Indications for Oocyte transfer
Old mares where it is not possible to retrieve an embryo
Oviductal disease
Mares with unexplained infertility
Describe proper vulvar conformation
vulva is 1/3 above and 2/3 below the pelvic bone
What is the most reliable way to examine the patency of the cervix?
digital examination during diestrus
What happens in maiden mares cervixes?
cervix will start to loose its functional integrity
The muscle layer undergoes a marked atrophy and the cervix becomes a collagenous tube that does not dilate
What are the different pathology of the cervix in the mare?
Fails to relax and open during estrus
Fails to close during diestrus
Adhesions
What is the most common bacteria causing endometritis in mares?
Streptococcus zooepidemicus
Escherichia coli
When would you perform a uterine biopsy?
Repeated embyronic death Repeated abortions Fail to respond to treatment Unable to diagnose uterine pathology with routine swab Prognosis of pregnancy
Grade III Uterine Biopsy
Severe fibrosis
Nest of glands isolated throughout the uterus
Severe damage to the uterus
What happens to edema as the mare reaches ovulation?
Edema starts to decrease toward ovulation
When do you see the most significant decrease in edema before ovulation in the mare?
18-36 hours pre ovulation
If you see high uterine edema what does that signal in the mare?
Low fertility
What are the causes of Failure to cycle in the mare?
Winter anestrous Transitional mare Pregnancy Endocrine Uterine Pathology
What causes Prolonged diestrus/pseudopregnancy in the mare?
CL lifespan prolonged beyond day 15
Diestral ovulations
Early embryonic death after maternal recognition of pregnancy 15-35 days
Failure of PGF 2 alpha release due to uterine abnormality: pyometra
What is the cause of Failure to cycle?
Aged mares stop cycling Limited number of oocytes Low body condition score negative energy balance Anterior Pituitary dysfunction Adrenal problem Tumors
What is the most common Gondal dysgenesis in the mare?
Turner’s Syndrome: small ovaries and infantile tract
What is the most common hermaphrodite?
Male Hermaphrodite
What are the tumors of the mare repro tract?
Teratoma Dysgerminoma Cystadenoma Granulosa cell tumor Granulosa-thecal cell tumor
What is the most common tumor of the equine repro tract?
Granulosa-Thecal Cell tumor
Clinical signs of Granulosa-Thecal cell tumors
Aggressive
Nymphomania
stallion-like
Anestrus
What is the treatment of Granulosa-Thecal cell tumors?
Remove ovary
How do you diagnose Granulosa-Thecal cell tumor in mares?
Measure Inhibin
What are the barriers to infection?
Vulva
vestibulo-vaginal fold
Cervix
Types of Endometritis in the mare
Breeding induced Persistent breeding induced Acute Bacterial Chronic Bacterial Chronic Degenerative
What causes Persistent Breeding Induced Endometritis in the mare?
Mares unable to evacuate residual fluid from the uterus due to poor uterine contractility or a poorly relaxed cervix are categorized as susceptible to uterine infections
What are the effects of uterine pathology on ovarian function?
Anestrus
Short luteal phases
Prolonged luteal phases
What type of bacteria causes short luteal phases?
Gram negative bacteria
What does Gram positive bacteria cause in the mare?
Inflammation affecting the uterine lining causing PGF 2 alpha to not be released
When should we culture the biopsy in the mare?
Mares that continue to accumulate fluid
Mares that ovulate with hyper-edema
Mares that show premature presence of uterine edema
Therapy for Persistent Mating induced Endometritis
Reduce the degree of inflammation
Reduce the time the fluid is accumulated
What are the predisposing factors of Chronic bacterial or fungal endometritis?
Poor perineal conformation
Cervical incompetence
Poor uterine contractility
What is the therapy for Biofilms in mares?
Acetylcisteine DMSO EDTA Gentocin Kerosene
Cause of Early embryonic death
Embryonic abnormalities Insufficient maternal P4 Failed MRP stress disease Inadequate endometrium Endometritis
Signs of Embryonic Death
Small size for gestational age
Irregular vesicle prior to day 20
Absence of a heart beat at day 28-30
Free fluid or disseminated edema in a pregnant mare
Abortion
loss of a pregnancy once the fetal stage has started
45+ days - birth
What is the most common cause of non-infectious abortion?
Twinning
What are the three routes of infection in the mare?
Transcervical
Hematogenous
Previous intrauterine infection
What is the most common cause of infectious infertility in the mare?
Herpes Virus
What is the most common cause of endometritis in the mare?
Streptococcus Zooepidemicus
What is the signalment for Equine Herpes Virus 1?
Mares 5,7,9 months of gestation
What are the lesions of EHV 1?
Hydrothorax
pulmonary edema
hepatic necrotic foci
eosinophilic intranuclear inclusion bodies in the foci in of the liver
EHV III
Coital exanthema Transmitted by the stallion Self-limiting Secondary bacterial infection Remove from service until heal
Clinical signs of EVA
Fever depression Rhinitis conjunctivitis Ventral edema Abortion 3-10 months
What is the only true venereal sexually transmissible disease in mares?
Contagious Equine Metritis
How do you diagnose Taylorella equigenitalis?
Culture penis, urethra, preejaculatory fluid and semen
When is the earliest a pregnancy can be diagnosed in the mare?
10- 16 days post ovulation
What are you checking for on days 28-32 on ultrasound in the mare?
Normal embryonic development
Presence of a heartbeat
Checking for one embryo
Vesicular morphology
Embyronic disk is always on the ventral side of the vesicle
What is responsible for maternal recognition in the mare?
Estrogen production + contact of the embryo = blockage of Prostaglandin production
When does the embryo fixate in the mare?
day 16
Describe the embryo on day 28-32
the embryo is in the middle of the vesicle and half is yolk sac and half is amniotic fluid
Describe the embryo at day 35-37
the embryo reaches the top of the vesicle and then becomes too heavy and the embryo falls to the ventral part of the vesicle
At what day is the embryo fully formed?
After day 45
When can you identify the genital tubercle?
day 55-65
What maintains the pregnancy until day 160?
CL
What occurs on day 100-120?
Gonads develop and produce estrone sulfate
What maintains the pregnancy after day 160?
progestagins from the fetal placental unit
What can cause twinning?
Ovulatory inducing agents
What is the method for twin reduction?
Spontaneous reduction Manual reduction Transvaginal Aspiration Manual trauma with membrane rupture Craneo-cervical dislocation Intracardiac injection of KCl Surgery Diet
Mummification
death in the absence of bacterial infection
Maceration
dead fetus with bacterial contamination
What is the treatment for Mummification or Maceration?
Removal of fetus
Uterine lavage and antibiotics
How deep should the amniotic and allantoic fluids be?
7.9 +/- 3.5cm and 13.4 +/- 4.4cm
What are the most reliable parameters to indicate fetal well-being?
FHR/FHR reactivity
Signs of Placentitis
Purulent vulval discharge
Udder development
Premature lactation
Cervical dilation
What is the therapy for Ascending Placentitis?
Antibiotic that crosses the placenta
Anti-inflammatories
Uterine relaxants
+/- Uterine Blood flow
What is common in older multiparous mares?
Vaginal varicose veins
What is a normal incidental finding in pregnant mares?
Allantoic vesicles
What is the most common Hydropic condition in mares?
Hydro-allantois
How do you treat Colic due to pregnancy in mares?
Altrenogest supplementation
Flunixin Meglumine
Antibiotics
When does Uterine torsion occur?
Late gestation
What is the treatment for Uterine Torsion?
Rolling
Flank approach
Ventral midline if foal is dead
How do you treat ventral abdominal edema?
diuretics and exercise
Characteristics of Pre-pubic tendon rupture of the mare
Cranial displacement of the udder
Obvious abdominal drop
Sero-sanguinous to bloody mammary secretion
Prolonged gestation
greater than 360-380 days
What are the causes of prolonged gestation?
Relationship to photoperiod
10 days longer in early spring than mid summer
Arrest of embryonic/fetal development may occur in early pregnancy lasting 3-5 weeks
What does Fescue cause?
Decreased milk production due to low prolactin
Prolonged gestation or even abortion
Weak or dead foals
Dystocia
How do you treat Fescue toxicosis?
Remove source 30-45 days before parturition
Domperidone
When should a pregnant mare be vaccinated?
10 months of gestation with all annuals and antibodies for colostrum
How should you prepare the mare for foaling?
Vaccination
Deworm
Nutrition
Exercise
What is the normal mare gestation length?
320-365 days
When would you open the Caslick before parturition?
1 weeks
In how many weeks is parturition due in the mare with udder enlargement?
2-4 weeks
In how many days is parturition due in the mare with clear watery secretions from the udder?
4-5 days
How many days is parturition due in the mare with Thick, sticky clear or yellowish exudate from the udder?
24-48 hours
How many days is parturition due in the mare with Thick, waxy exudate on the udder?
24-48 hours
Describe the first stage of labor in the mare
Cervix relaxes uterine contractions Fetal rotation Restless mare sweating
Describe the second stage of labor in the mare
Uterine contractions intensify Sweating fetus enters the birth canal Chorio-allantoic membrane ruptures Abdominal contractions Amnion appears at vulva
What are the requirements for induction in the mare?
greater than 330 days of gestation
Cervix is open atleast 3 fingers
Colostrum or milk in udder
Why would you induce at 315 days?
compromised mare
What is the effect of using Prostaglandin for parturition induction?
Explosive birth with torn cervix
Foals broken ribs and ruptured bladder
What is the method of choice for inducing parturition in the mare?
Oxytocin
What is the method of choice for inducing parturition in a compromised mare?
Steroids
Describe stage three of labor in the mare
Expulsion of the placenta or fetal membranes
Normal delivery within 3 hours
How many layers of the Placenta in the mare?
6 layers
What type of placenta do mares have?
Epitheliochorial
Diffuse
Micro-cotyledonary
Which horn is often the horn that becomes torn in the mare?
The non pregnant horn
Dystocia
The inability of the mare to culminate the second stage of labor
When do you suspect Dystocia?
if the mare is actively straining, chorioallantois breaks and no visible progress in 10-15 minutes
Red Bag
Premature Placental Separation
What are the problems associated with Red Bag deliveries?
Prolonged labor
Meconium release
Foal Anoxia/Asphixia
Dummy foal
How do you relieve Dystocia in the mare?
Traction Fetotomy C-section Reposition Repulsion and reposition Flotation
What are the options for C-section in the mare?
Flank
Ventral
How do you minimize contractions while fixing the dystocia?
Injectable clenbuterol
Sedation with xylazine and butorphanol
What are the risk factors for Septic Metritis?
Cleanliness of foaling area
Retained placenta
Ascending placentitis
Obstetric manipulations
Clinical signs of Septic Metritis
Fever depression tachycardia injected mucous membranes Positive digital pulses Distended uterus with large amounts of fluid
What is Septic Metritis associated with in the mare?
E. coli
Klebsiella pneumoniae
Therapy for Septic Metritis
Systemic antibiotics
NSAIDs
Prevention of endotoxemia-laminitis complex
Uterine Lavage
Therapy for Hemorrahge Post-Partum clinical signs
Xylazine and Butorphanol Replenish fludis Aminocaproic acid Yunnan baiyao IV therapy with Formalin
Uterine tears/rupture clinical signs
Depression
Anorexia
colic
fever
Therapy for Uterine tears/rupture
Surgical Oxytocin Antibiotics NSAIDs Fluid therapy abdominal lavage
What is contraindicated in Uterine tears/rupture therapy?
Uterine lavage
Risk factors of Uterine Prolapse
Dystocia
Retained placenta
Persistent straining
Therapy for Uterine Prolapse
Wash and assess uterus for tears
Start replacing the uterus from the most distal place
Uterine lavage
Supportive therapy
Rectal prolapse
forceful straining during dystocia resulting in rectal prolapse could result in avascular rectal necrosis
Recto vaginal fistula
Foal’s perforates the roof of the vagina and wall of rectum
Treatment for Recto Vaginal fistula
Heal by second intention
Repair surgically if feces are still found in the vagina or vestibule
Third degree perineal lacerations
tears of the ventral rectal wall and dorsal vaginal wall forming a cloaca
How do you treat bladder atony?
Buthanecol
Risk factors of Retained Fetal Membranes
Abortion Induction of parturition C-section Dystocia Twin pregnancy Placentitis Pain Hydropic conditions Hypocalcemia Low Vit. E and Se
Treatment for Retained Fetal Membranes
Oxytocin IV calcium Borogluconate Burns technique Manual removal Antibiotics: TMS in the uterus
Burns Technique
infusion of large volume of fluid in the unruptured chorio-allantoic space to stimulate endogenous oxytocin release
When is the foal heat?
day 6 after parturition
ovulate on day 10
When do you have uterine involution in the mare?
Day 14
What method of collection would you use in a stallion with neurologic problems or lameness?
Ground collection
What drugs are used for chemical ejaculation in the stallion?
Norepinephrine
Imipramine
Xylazine
Describe the stallion semen characteristics
50mL 120x10^6 sperm concentration 5-15x10^9 total sperm Greater than 60% sperm motility Greater than 60% normal morphology
What is a common perm abnormality in the stallion?
Abaxial aberration of the tail
What is Spermatogenic epithelium in the semen of the stallion a sign of?
Testicular degeneration
What does low seminal plasma ALP mean?
there is a blockage in the epididymis
What does a high seminal plasma ALP mean?
no sperm present in the testes
How much sperm is present in fresh semen for AI?
500 milllion
How much sperm is present in cooled semen for AI?
1 billion
How much sperm is present in frozen semen for AI?
Load 800 million to 1 billion
Minimum of 240 million after thawing
Pyospermia
pus in the semen
Hemospermia
blood in the semen
Urospermia
Urine in the semen
If you find pyospermia in the presperm fraction where is it coming from?
bulbourethral glands, urethra
If you find pyospermia in the sperm rich fraction where is it coming from?
Epididymis
ampullae
If you find pyospermia in the sperm poor fraction where is it coming from?
Prostate
vesicular glands
If you find pyospermia in the gel fraction where is it coming from?
Vesicular glands
What is the treatment for hemospermia?
Sexual rest
depends on the source of the blood
What is a source of hematuria in geldings?
Tear in the mucosa of the urethra
What is the treatment for a tear in the mucosa of the urethra in geldings?
Cauterize
Sexual rest
Causes of Urospermia in the stallion
Cauda equina neuritis EHV-1 HPP Cystitis or urolithiasis Fractures osteomyelitis neoplasia idiopathic
Treatment for urospermia in stallions
Completely empty bladder before ejaculation
Furosemide to dilute any urine
Bladder lavage
Dilute raw semen immediately
Alpha-adrenergics: imipramine and Phenylpropanolamine
Retrograde ejaculation in the stallion
Semen in the bladder
When is normal testicular descent in the stallion?
last 30 days in utero or first 10 days after birth
In what breed might you find Cryptorchidism?
QH
Percheron
ASH
ponies
How do you diagnose Crytorchidism?
Rectal exam US Resting testosterone concentration hCG/GnRH stimulation Basal estrone sulfate Anti-mullerian hormone
What is the cause of testicular trauma in stallions?
Kick by mare
What is the treatment for testicular trauma in the stallion?
NSAIDs Ice hydrotherapy sling hand walking
What is the treatment for testicular rupture?
remove the ruptured teste to save the normal teste from damage
What is the treatment for Infectious Orchitis?
Antimicrobial therapy supportive therapy
Unilateral orchiectomy
Why should you perform a unilateral orchiectomy on infectious orchitis in the stallion?
To save the normal teste from heat and swelling
What is the most common neoplasia in the stallion?
Teratoma
What neoplasia is malignant in older stallions?
Seminoma
What solution should you preserve testicular neoplasia in for histopathology in the stallion?
Bouin’s solution
Oligozoospermia
small amount (low concentration) of sperm
Asthenozoospermia
sperm do not move (reduce sperm motility)
Teratospermia
abnormal sperm morphology
Azoospermia
no sperm int he ejaculate
What is the treatment for testicular degeneration?
no treatment
What does testicular degeneration cause?
Oligozoospermia
Asthenozoospermia
teratospermia
azoospermia
How do you diagnose testicular degeneration?
biopsy
What cause of testicular degeneration can the testes recover from in the stallion?
prolonged elevated temperature
Hydrocele (vaginocele)
serous fluid between visceral and parietal layers of vaginal tunic
What is the cause of Hydrocele in the stallion?
Idiopathic
Extension from ascites
What is the treatment for Hydrocele in the stallion?
Spontaneous resolution
move to cooler environment
Exercise
Varicocele
Dilation of vessels of pampiniform plexus
What is the cause of Varicocele in stallions?
Incompetent testicular vein
What is the treatment for severe/acute testicular torsion in the stallion?
Surgical removal
What are the complications of detorsing a long term spermatic cord torsion
reprofusion injury and breach of blood teste barrier of the good teste
What is the treatment for penile hematoma?
Minimize hemorrhage
Tight bandage
prevent sexual arousal
Paraphimosis
inability to retract penis
Treatment of paraphimosis in stallions
Resolve cause
support penis
reduce swelling
return prepuce
Complications of paraphimosis in stallions
Phallectomy
What causes Paraphimosis in stallions?
Trauma
systemic disease
neurological
phenothiazine tranquilizers
Priapism
Persistent erection without sexual arousal
What cause priapism in stallions?
Phenothiazine tranquilizers
neurological
Treatment of priapism in stallions?
Anticholinergic
Beta 2 adrenergic drugs
Phenylephrine
Surgical irrigation
What is the most common penile neoplasia in stallions?
Squamous cell carcinoma
High flow priapism
Arterial supply affected
Low flow priapism
Venous drainage affected