Theriogenology
Terms
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- Name four reasons for raising sheep.
-
Wool
Meat
Milk
Pets - What are 2 types of Sheep management systems?
-
Extensive
Intensive - What are the 5 Categories of Sheep Breeds?
-
1. Meat = Callipyge (generally dark faced breeds)
2. Wool (Ex. Lincoln)
3. Dual Purpose = meat and wool (Dorset is the best dual purpose breed)
4. Synthetic/Cross breeds
5. Reproductive breeds = wants ewes that can have large litters (want to select ewes that can have twins or triplets) - What is flushing?
-
-The act of increasing nutrient uptake of ewe 20-30%, 2-3 weeks prior to breeding
-This is especially important for thin ewes, to get them into breeding condition (fat ewes don’t respond well to flushing and are poor breeders) - When should you flush a ram?
- 8 Weeks prior to breeding.
- What are 3 ways to preg check a ewe?
-
-Non-return to heat at 16-17 days
-Transrectal U/S at 20+ days
-Abdominal U/S at 35 days ***U/S is the only practical way to preg check ewes*** - Describe proper ewe management during pregnancy.
-
-Prevent pregnancy toxemia by providing proper nutrition
-Exercise
-De-worm
-Vaccinate
-Medicate
-Shearing (to be coordinated w/ the annual shearing), tagging, crutching
-Shearing allows easy access to the nipple for the lamb and causes the ewe to get cold and hopefully persuade her to lamb inside - When does puberty occur in a sheep?
-
5-15 months.
When the lamb attains greater than 60% of his adult body weight. - What are some factors that affect the onset of puberty?
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-Time of lambing
-Lambs born in June will probably skip their first cycle
-Lambs born in Jan. and fed well will probably have their first cycle in fall
-Nutrition
-Breed (Finn> Suffolk> Rambouillet- tend to have late sexual maturiy) - How much time passes between ovulations in a sheep?
- 16-17 days
- How long is a ewe actually in heat during one ovulation?
-
10-40 hours.
Average = 36 hours - When can you AI a ewe?
- 18-24 hours post standing estrous
- List some sexual behaviors in Sheep.
-
Nosing
Flehman
Seeking
Nudging
Mounting - When do sheep tend to breed?
- Short days
- Name some breeds that breed put of season.
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Dorset
Finn
Rambouillet - When you should give up trying to breed a ewe.
-
When the cops show up.
Don't try to breed a ewe more than 3 times - What is the gestation period for a ewe?
-
140-155 days
Average = 148 - What are some first signs of parturition in a ewe?
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Restlessness
decreased appetite
mothering
swelling of vulva
colostrums
decreased body temp. - in sheep, how long do first stage uterine contractions last?
- 2-8 hours
- What happens during the second stage of parturition in a ewe?
- Cervix is stretched and oxytocin is released. Abdominal pressing can last from 20 minutes to 2 hours.
- In what age range are ewes most prolific?
- 3-6 years
- how long is the post partum period for a ewe? (how long before she can have a productive estrous cycle?)
- 30 days
- How should you supplement the nutrition of an expecting ewe?
- 50% increase in nutrients over the last third of gestation.
- When should you wean a lamb?
- 8 weeks
- What are the seven steps to synchronizing estous in sheep?
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1. Give progesterone in spring and fall
-Spring = need to give FSH in addition to progesterone
-Fall = only need to give progesterone
-Synchronize NO more than 5 ewes/day/ram
2. Give prostaglandin during breeding season
-Prostaglandin ONLY works when ewe is cycling
3. Ram effect
-The rams pheromones and vocalization can help to synchronize the ewes
4. Daylight effect
5. Superovulation/increased number births
6. Steroid hormone immunization
-Steroid inhibits the negative feedback so more FSH can be released
-This increasing lambing % by 20-30%
7. Synchromate B (has been pulled off market) - When is the earliest you can induce parturition in sheep?
- 141-142 days of gestation
- What two drugs can be used to induce parturition in sheep and when will they have an effect?
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Dexamethasone - lamb will be born within 72h
Estrogen - lamb will be born wihin 24h -
What are the 3 major causes of abortions in sheep?
What are some other agents that cause abortions? -
1. Vibrio (Campylobacter fetus)
2. Toxoplasmosis
3. Chlamydia
Others include:
-Border disease (hairy shaker lamb)
-BVD
-Salmonella typhimurium
-Listeria monocytogenes
-Lepto
-Bluetongue virus
-Coxiella burnetti (i.e. Q fever)
-Sarcocystis - Which, of the major abortion causes in sheep, can cause early abortions?
- Toxo
- What are the gross lesions associated with Vibrio abortions in sheep?
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-Placentitis w/ edema
-Necrosis of cotyledons
-Intrauterine death
-SQ edema and fluid
-Necrotic liver foci (rare, only occurs in 40%) - What are the gross lesions associated with Toxo abortions in sheep?
- -Cotyledons have gray/white foci (1-3mm in size)
- What are the gross lesions associated with Chlamydia abortions in sheep?
- -Chorionitis w/ elementary bodies (seen on impression smears)
- How do you control Vibrio abortions in sheep?
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-Hygiene
-Vaccine
-Mass medication -
How do you control Toxo
abortions in sheep? -
-Control young cat population on farm (cats are #1 transmitter of oocyts)
-Rumensin (antibiotic) - How do you control Chlamydia abortions in sheep?
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-Hygiene
-Tetracycline
-Vaccine - What are some clinical signs of Vibrio abortions in sheep?
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-Late pregnancy abortions
-Stillbirths
-Weak lambs
-Metritis
-Peritonitis - What are some clinical signs of Toxo abortions in sheep?
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Early pregnancy:
-EED
-Fetal death
-Mummies
Late pregnancy:
-Abortion
-Perinatal lamb loss - What are some clinical signs of Chlamydia abortions in sheep?
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-Late abortions
-Still births
-Weak lambs
-Fetal mummification
-Congenital infections abort first pregnancy - How do you treat sheep abortions?
-
1. Diagnosis is the #1 priority (submit sample for histopathology: placenta, fetus, blood)
2. Tetracycline
3. Isolation
4. Sanitation
5. Monensin
6. Bovatec
7. Prevent zoonoses (Toxo and Q-fever) - How do you prevent sheep abortions?
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1. Vaccinate for vibrio and EAE
2. Medicate w/ chlorotetracycline for vibrio and EAE
3. Cat control for Toxo
4. Med w/ monensin and bovatec for Toxo - What are some obstetric rules to live by?
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1. Be clean
2. Be gentle
3. Use LOTS of lubrication
4. Check for cervical dilation (ringwomb = syndrome where ewes don’t dilate)
5. Double check presentation
6. Size of pelvis to size of lamb
7. C-section = $, future reproduction, lamb and ewe survivablility - What are some advantages of early detection of dystocia in sheep?
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1. Increase # of lambs born
2. Decrease ewe mortality
3. Allow intervention - How do you deal with sheep dystocia?
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-Intervene when there has been 1-1 ½ hrs. of no progress
-Intervene if there is malposition (i.e. unilateral/bilateral shoulder flexion or breech)
-Give an epidural of lidocaine to help alleviate straining
-Lubricate, use good hygiene, give antibiotics, and vaccinate (tetanus antitoxin)
-Treat ringwomb w/ c-section, cervical incision, manual dilation, estrogens
-Any ewe that has had dystocia should be culled
**Check for multiple lambs - What are some risk factors for vaginal prolapse in sheep?
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-multiple ewes (?? multiple lambs?)
-Excess estrogen
-Pushing, crowding at feed bunk - Do you want to stitch a ewe's prolapsed vagina high and tight or low and away?
- High and Tight
- What dietary changes can be made to prevent a sheep from getting a prolapsed vagina?
- Take away hay and feed corn and oats because hay takes up too much room in the rumen.
- What is the Tx for a sheep vaginal prolapse?
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-Retainer
-Buhner stitch
-Want to place vagina high and tight - What are some characteristics of a uterine prolapse?
-
-Seen post lambing due to difficult birth or hypocalcemia
-Different from vaginal prolapse b/c with uterine prolapse you can see the cotyledons
-More of an emergency than vaginal prolapse - What is the Tx for a uterine prolapse?
- -Clean, replace, suture, systemic antibiotics
- What are some problems that can cause fertility problems in rams?
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Pizzle rot
Scrotal mange
Scrotal Abscesses
Epididymitis - What is the etiologic agent for Pizzle Rot?
- Balanoposthitis
- What is the etiologic agent for Scrotal Mange?
- Chorioptes bovis
- What is the etiologic agent for Scrotal abscesses?
- -Actinomyces pyogenes
- What is the etiologic agent for Epididymitis?
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-Brucella ovis
-Causes spermatic granuloma of epididymal tubules
-Actinobacillus seminis
-Severe, acute, painful
-Causes epididymitis in peripuberal ram lambs - What is the Tx for pizzle rot?
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-Clean
-Furacin ointment
-Ammonium chloride (1 gram TID for several days) - What is the Tx for Scrotal Mange?
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-Ivermectin
-Fenvalerate
-Coumaphos
-Trichlorfon - What is the Tx for scrotal abscesses?
- Drain
- What is the Tx for epididymitis?
-
-DO NOT VACCINATE
-Test and cull - How does the estrus cycle in goats differ from sheep?
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-More strictly limited to fall than sheep
-21 day cycle
-12-36 hrs. of estrus
-AI after 12-24 hrs after onset of estrus
-Doe will be restless, vocal, wag tail, swollen vulva, and have decreased milk production while in estrous - What is the gestation period for a goat?
- 140-155 days (median 2-3 days longer than ewe)
- How can you, or more importantly, how can you not diagnose pregnancy in a goat?
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-Increased progesterone during late gestation CAN NOT diagnose pregnancy
-Look for soften cervical (d. 30) or cervix out of reach (d. 50)
-Udder is NOT dependable for diagnosis of pregnancy - WHat are some causes of doe infertility?
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-Endometritis
-Pyometra
-Cystic Follicles
-Hydrometra (pseudopregnancy)
-Treat w/ PGF2-alpha or surgery - What are some causes of abortions in goats?
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-Toxo
-Chlamydia
-Salmonella
-Brucellosis melitensis (may not be a cause in the US)
-Listeria
-Lepto (greater importance in does than ewes, they will abort at the time of infection)
-Angora goats are habitual aborters due to their adrenal cortical depletion - What are some Causes of Buck Infertility?
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-Spermatic granuloma (associate w/ polled gene)
-Occurs between the head of epididymis and testes - What are some characteristics of AI in goats/sheep?
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-Can use fresh or frozen semen
-50-350 million live sperm per insemination
-Can AI intrauterine or intracerival
-Can use a laparoscope
-AI 12-24 hours after start of estrous
-60-70% first service conception rates - What are some purposes for llamas?
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-Llama’s are guard animals (used w/ sheep to protect them from dogs, coyotes)
-Pack animals
-Fiber
-Meat - What is special about a llama's testicles?
- Located in the perineal region.
- What are some characteristics of llama semen?
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-Highly viscous
-Milky white color
-Slow motility (no mass motility as seen w/ ram sperm)
-> 50% normal/desirable - What are some characteristics of llama penises?
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-Penis is fibroelastic w/ sigmoid flexure
-Adhesions present between body of penis and sheath in prepuberal animals
-Urinate backwards between legs
-Corkscrew appendage at tip used to dilate cervix and enter uterus during breeding
-Stimulation – protractor penis muscle directs forward - What are some characteristics of llama estrus cycles?
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-Periods of long sexual receptivity (36 days) and short periods of non-receptivity (48 hrs.)
-Rhythmic increase and decrease due to follicle maturation and atresia
CL Function:
-Peaks 9 days post mating
-Maintains pregnancy
-Luteal diameter and plasma progesterone highly correlated
Ovulation:
-Increase serum LH 15 minutes after onset of copulation (i.e. induced ovulators)
-26 hrs. after natural mating they ovulate
-Can induce ovulation w/ GnRH
-New follicles develop between 12-16 days - What is the gestation period for a llama?
- -335-365 days (avg. 345)
- In what part of the uterus do most llama pregnancies happen?
- Left horn (90-95%)
- How do you diagnose pregnancy in llamas?
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-Sexual behavior/Lack of estrous
-Ballotment/External palpation
-Rectal palpation
-P4 levels >2ng/ml after day 18 indicates active CL and pregnancy
-Ultrasound at 15 days (transrectal) and 50 days (transabdominal)
**Diffuse epitheliochorial placenta** - What are some reasons for llama fetal deaths?
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-High incidence of early embryonic death in the first 30 -90 days (decreases after 30)
-Rebreeding too soon after parturition
-Inbreeding
-Uterine infection and pathology
-Old age
-Stress - Describe the stages to llama parturition.
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Stage I = Preparatory (1-6 hrs.)
-Stage II = Fetal expulsion (<60 minutes)
-Stage III = Placental expulsion (4-6 hrs.) - When does ovarian activity resume after parturtion in a llama?
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-Ovarian activity resumes 3 days postpartum
-May breed at this time but they do not recommend till after day 15-20 days - How much colostrum does a cria need?
- 4-10% of body weight in first 10 to 12 hours.
- What are some congential defects that lead to infertility in llamas?
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-Gonadal aplasia and hypoplasia
-Persistent hymen
-Uterus unicornis
-Double cervix and intersex (hermaphrodites)
-Segmental aplasia - What are some acquired problems that lead to infertility in llamas?
-
-Metritis/Endometritis (generally caused by Strep)
-Endometrial cysts = can determine via ultrasound
-Cystic ovaries = variable response to GnRH or HCG - How do you diagnose infertility in llamas?
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-History
-Rectal
-Ultrasound
-Speculum
-Culture
-Biopsy
-Hormone analysis - Name some equine ovarian structures.
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-Follicle
-Ovulation Fossa
-Corpora Hemorrhagica
-CL
-Oviduct (infundibulum, isthmus, ampulla, oviductal papilla, uterotubal junction – which is the sperm reservoir) - What are the 3 physical barriers to contamniation of the equine uterus?
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1.Vulva
2. Vestibule
3. Cervix - What are some congenital and acquired defects that cause infertility in mares?
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CONGENITAL DEFECTS:
-Persistent hymen
-Tubular agenesis of cervix, uterus, oviduct
ACQUIRED DEFECTS:
-3rd degree perineal laceration
-Rectovaginal fistula - What are some guidelines to performing an exam of the repro tract of a mare?
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Restraint: put animal is the stocks
Protective Wear: plastic palpation sleeve
Lubricatin: can’t ever get enough lube
Manure removal: remove manure first before trying to find landmarks – cup hand dorsally to try and prevent rectal tears (if you do tear – better to tear dorsally than ventrally)
Anatomic Orientation: Brim of pelvis, cervix, uterus, ovary - What are the components of taking a history for a BSE for a mare?
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1. Age
2. Parity
3. # Foals
4. Last foal date
5. Stallion fertility/management/number
6. Method of service (live, cooled, frozen)
7. Dystocias
8. EED = Early Embryonic Death
9. Abortions/Stillbirths = what stage in pregnancy did they occur
10. Endometritis/postbreeding
11. Urine pooling/caslicks
12. Twins = “Once a twinner always a twinner†- What are the components of a Vulvular Conformation Assessment in a mare?
- -Look at vulva, vestibule, cervix
- What are the components of a Transrectal Palpation in a mare?
-
-Check for:
-Cervical tone
-Uterine symmetry
-Pregnancy
-Ovarian symmetry
-Ovulation fossa
-Paraovarian cysts - What are the components of a Endometrial Cytology in a mare?
-
-Looking for active inflammation
-Can diff quick finding and get immediate results
-May see PMNs, fungal hypae, yeast, bacteria
-Should NORMALLY see epithelial cells and mucus - What are the components of a Biopsy in a mare?
-
-GRADE I:
-80% live foal rate
-Glandular density
-Tall columnar epithelium
-Tortuous glands
-GRADE II A:
-Endometrial edema
-Potentially reversible
-Low glandular density
-Dilated lymphatics
-Cuboidal epithelium
-GRADE III:
-Glandular nesting
-Fibrotic rings
-<10% probability of foaling - What are the components of a Hysterocscopy in a mare?
- -May see oviductal papilla, adhesions, and will allow for proper semen deposition
- What are some benefits of doing cytology on the equine uterus?
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-Rapid results
-Can differentiate PMNs, macrophages, yeast, fungi, bacteria - What are the components of the male reproductive tract?
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-Vesicular glands (seminal vesicles are unique to the horse)
-Large ampullae
-Bilobed prostate
-Bulbourethral glands - List some potential venereal pathogens that may be transmitted in semen?
-
Bacterial:
-Klebsiella
-Pseudomonas aerugenosa
-Taylorella equigenetialis (CEM)
Viral:
-EVA
-Equine Coital Exanthema (EHV-3)
Protozoal:
-Trypanosoma equiperdum - Summarize minimal criteria that a stallion should meet to be classified as a satisfactory prospective breeder
-
-Free of undesirable, potentially heritable defects, behavioral disorders, or transmissible diseases
-Posses no physical trait that would interfere w/ mating ability, semen quality, sperm output
-Ejaculate minimum of 1x109 pm (billion), morphologically normal sperm in the 2nd of 2 ejaculates 1 hr. apart after 1 week of sexual rest - Describe an Assisted Vaginal Delivery (AVD).
-
-Mare is awake and minor assistance needed to deliver an intact foal
-Standing is better than recumbent b/c the weight of the fetus in uterus helps to realign stuff
-Xylazine and Butorphenol will put the front end to sleep and not the back end
-too much of the drug and the mare can lose control of back end - Describe a Controlled Vaginal Delivery (CVD).
-
-Mare is anesthetized and clinician is in complete control of vaginal delvery
-Use short term anesthesia
-Elevate hind quarters => decreases uterine contractions and gets weight of abdominal contents off the fetus - Describe a Fetotomy.
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-Fetus is dead and cut is made to deliver vaginally
-very poor prognosis for future reproductive function in the mare if more than one cut is made - Describe a Cesearean Section.
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-Mare is anesthetized and fetus is removed through an incision in the uterus
-mares reproductive future is more positive than w/ fetotomy - Describe the more common obstetrical procedures used to correct dystocia in the mare by mutation and traction
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Mutation: manipulation of fetus to return it to normal presentation, position and posture
Repulsion: forced movement of fetus from pelvis to abdomen
-Can use:
-Clenbuterol = smooth muscle relaxant
-Isoxuprine = muscle relaxant
-Buscopan = smooth muscle relaxant - What are some common ways a foal can be malpositioned?
-
Retention of forelimb (carpal flexion)
Retention of elbow on pelvic brim (very common)
Lateral/Ventral deviation of head and neck
True breech (transverse ventral presentation – back of fetus or 4 feet on exam) - Define Fetal presentation.
- relationship of spinal axis of fetus to that of dam
- Define Fetal position.
- relationship of dorsum of fetus to the quadrants of maternal pelvis
- Define Fetal posture.
- relationship of extremities (head and front limbs should be extended) **most common abnormality
- How do you treat a mare's retained placenta?
-
-Systemic antibiotics
-Penicillin and Gentacin
-NSAIDS
-Flunixin, Ketofen, Butorphenol??? (phenylbutazone)
-Oxytocin
-Uterine Lavage - How do you treat a Uterine Prolapse in a mare?
-
-Control straining w/ epidural
-Coat uterus w/ Vaseline
-Cover w/ plastic bag
-Elevate uterus to level of pelvis - How do you treat an invagination of uterine horn in a mare.
-
-Manual removal of placenta
-Transect portion of placenta
-Uterine lavage - How do you treat a Uterine rupture in a mare?
-
-Keep mare quiet
-NSAIDS
-Naloxone HCL (opioid antagonist ??) - What are the components of the mare's uterine defense mechanisms?
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1. Physical barriers (vulva, vestibule, cervix)
2. Opsonization of bacteria by PMN’s
-Estrogen: increase in PMN function
-Progesteron: decrease in PMN function
-Ab’s and compliment
-Resistant mares have higher levels of compliment
3. Physical clearance
-Cervical relaxation
-Cervix relaxes and peak uterine contraction
-Uterine position
-Uterine contractions
-Lymphatic clearance - Is a positive endometrial culture definitive for a diagnosis of endometritis?
- No
- What are the most common locations for genital infections in the mare?
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-Cervix
-Vagina
-Salpinx - List the most common organisms associated w/ endometritis in the mare
-
Bacterial:
-Beta-hemolytic strep zooepidemicus
-E. coli/enterobacter
-Pseudomonas
-Klebsiella
Yeast/Fungal:
-Candida albicans
-Aspergillus
Contagious Equine Metriris (CEM):
-Taylorella equingenitialis - What is the average gestation time for a mare?
- 320-326 days
- What is the seasonal influence on gestation?
- Jan – Mar the gestation is 5-10 days longer
- What are the nutrition requirements for a pregnant mare?
-
-Want mares BCS to be 6-7
-From time of conception to 8 months of pregnancy have the mare on maintanence
-9-11 months of gestation: 1.1-1.2 x’s maintenance (60-65% of fetal growth is occurring during those months)
-Should be a forage based diet (alfalfa/grass)
-Ca:P ration 1:1 (.2% and .3%)
-Se, Cu, Zn, I, Mn - What are some health care considerations that should be made for a pregnant mare?
-
-EHV-1: vaccinate at 5,7,9 months
-EWT: vaccinate 1 month prior to due date
-WNV: vaccinate 1 month prior to due date
-Deworm q. 60 days for tapeworms
-Give ivermectin day of foaling b/c strongyloides westeri larvae can be in milk (encysted larvae are resistant => stress of lactation => uncyst => pass in milk => intessusseption in foal - What are some changes to the mammary glands that predict parturition in the mare?
-
Colostrum > 60 g/L
-Ca, at 200 ppm 48 hrs. prior to parturition
-Ca 300-500 ppm 24 hrs. prior to parturition - Describe the progression of events in the three stages of labor
-
STAGE 1: PREPARATORY:
-30 minutes to 4 hrs.
-Fetal rotation
STAGE 2: DELIVERY:
-20-30 minutes
STAGE 3: EXPULSION OF PLACENTA:
-30 minutes to 3 hrs.
-If mare hasn’t passed placenta by 2hrs. intervene and give oxytocin - Outline the methods for inducing delivery in mare
-
Requirements for inducing ovulation:
-335 days of gestation
-Mammary gland development
-Relaxation of pelvic ligaments
-Colostrum
-Milk Ca> 300ppm
Inducing delivery:
-Oxytocin (drug of choice)
-causes milk let down, myometrial contractions and uterine involution and expulsion of retained placenta
-PGF2alpha - Describe the physiologic changes during the transition from anestrus to ovulation
-
-Anestrus:
-Low GnRH, FSH, LH, E2, P4
-During Transition:
-↑ GnRH => ↑ FSH
-LH synthesis lags behind FSH synthesis
-Multiple follicular waves occur 14 days apart
-After 3 waves (42 days) the mare is transitioned and ready to ovulate
-Mare is ready to ovulate when there is an INCREASE in estrogen 17B => LH release => Ovulation - List guidelines for an artificial lighting program
-
-Photoperiod controls cyclicity
-16 hrs. of daylength is required to advance cyclicity
-45-60 days to induce 1st ovulation
-Add day length to the pm
-Incremental increases is NOT necessary - Discuss the rationale for progestogens in the transition period of mares
-
-To shorten the duration of transition
-Transitional mares have insufficient LH stores to induce ovulation
-Progestens inhibit LH release resulting in storage of LH in pituitary gland (does not affect FSH so mare can still get follicular growth
-Treat for 10-14 days w/ altrenogesto rP4 during mid to late transition
-Requires a follicle 25mm or greater in size - Give the length of the embryonic, fetal, and neonatal periods in horse
-
Embryonic = conception until d. 40
Fetal = d. 40 until parturition
Neonatal = birth until d. 28 - What are the maternal signs of embryonic loss in the mare?
-
-Low P4
-Large cysts
-Endometrial fibrosis can prevent proper migration of fetus
-Post-mating endometritis
-PGF2alpha produced and causes lysis of CL - What are some changes in the uterine environment that are signs of embryonic loss?
-
-Endometritis (most common)
-Periglandular fibrosis
-Endometrial cysts - Discuss management options for embryonic death in mare
-
-Ultrasound monitoring q. 1-3 days
-P4 supplement (not sure if it works but won’t hurt anything)
-If no fetal heart beat by d. 30 must manually crush the vesicle
-give PGF2alpha to lyse the CL and end pregnancy and then do a uterine lavage - List the causes of placental dysfunction in mare
-
-Uterine fibrosis
-Hydroallantois
-Placental edema
-Infectious diseases - List the more common infectious causes of abortion in mare
-
1. EHV-1
-prior history of URT infection in young stock
-Fetal hepatic intranuclear inclusions is pathognomotic
2. Mycotic placentitis
-Aspergillus
3. Bacterial placentitis
ASCENDING BACTERIA
-Beta hemolytic Strep Zooepidemicus (#1 cause)
-E.coli and pseudomonas are other causes
HEMATOGENOUS BACTERIA
-EVA
-Lepto (in the fetus)
- Nocardia - Design a thorough diagnostic approach to an abortion problem on a broodmare farm
-
-Submit specimens for histopathology (aborted fetus and placenta)
-Post-mortem exam:
-Intact stomach and contents
-Liver
-Kidney
-Spleen
-Adrenals
-Placenta
-Uterine fluid – run CS and cytology
-Serology of fetus and am - When do you Dx a twin foal?
- day 14-16
- Describe Conceptus mobility throughout uterus.
-
-Embryo is highly motile and moves through out the all 3 areas of uterus (the 2 horns and body)
-peak motility d. 11-12 (the motility is associated w/ uterine contractions)
-the estrogens produced by the early embryo contribute to contraction and motility of embryo
-the embryo must migrates in at least 2/3 of the segments for maternal recognition
-restriction to the 1/3 of the uterus may cause the mare to return to estrus on day 14
-large, cystic follicles can also restrict migration and lead to problems w/ recognition - When does the foal embryo enter the uterus?
- day 5-6
- when and how does embryonic vessicle fixation occur?
-
-Occurs d. 14-16 and the vesicle localizes at the base of the horn
-Need both P4 and E2 (produced by embryo) for this to occur
-Will see: increased vesicle size, increased muscular contractility (thickening of the dorsal uterine wall)
-If endometrial edema is noted that is not good - How does maternal recognition of the foal occur. what happens if the mother does not recognize the embryo?
-
-The embryo’s migration is what helps the mare to recognize the pregnanct
-if the mare has not recognized the embryo by day 14 then PGF2alpha is released and the CL is lysed - Discuss emdometrial cup formation.
-
-Formed in the chorionic girdle of trophoblasts
-Formed d. 25-38 and lasts until d. 150
-Cup releases of eCG and PMSG
-eCG has FSH and LH like activity to cause formation of accessory CL’s
-accessory CL’s are formed by d. 35-40 and last until d. 150-200 - Discuss Supplemental CL formation.
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-Primary CL last until d. 25-30 and the accessory CL pick up the need to produce progesterone around d. 30-40
-D. 40-50 the progesterone comes from the fetus (called 5alpha-pregnanes) - Discuss Placentation in the mare.
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-Fixed by d. 16
-True placentation = occurs gradually
-Trophoblastic microvilli = d. 25
-Endometrial cups = d. 35 (the cup will eventually make eCG and will persist even if pregnancy is lost)
-Microoctyledons = d. 45
-Microplacentomes = d. 150 - Where does P4 come from during equine pregnancy?
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-Initially comes from primary and accessory CL’s
-D. 40-50 comes from fetal progesterone - Where does E2 come from during equine pregnancy?
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-Mare
-Placental
-Fetal gonads
-d. 150 dominant source is fetal gonads and placenta - Where does eCG come from during equine pregnancy?
- -Endometrial cup
- When can you likely diagnose an equine pregnancy transrectally?
- Day 15
- When can you likely diagnose an equine pregnancy via Trans-abdominal US?
- day 150 - 210
- What does estrogen sulfate have to do with equine pregnancy?
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-High levels of E2 produced by the conceptus as early as D. 12
-D. 60-100 estrogen sulfate> estrogen
-Total E2/P4 assays are useful in assessing fetal viability - x
- x