Reproductive history is part of a breeding soundness exam, what questions should be asked?
has a heat cycle been observed? when?
interval between heat cycles
length of estrus cycles
breeding dates
previous foaling dates
abnormal/ assisted foalings
# of previous pregnancies
# of breedings for conception
A) Uterine horn
B) Oviduct
C) Infundibulum
D) Broad ligament
E) Cervix
F) Vagina
G) Vulva
H) Uterine body
The ovaries can be examined via rectal and ultrasound evaluation. What are we looking for in these exams?
presence of follicles (number and size)
CH
CL
Abnormal follicles
The uterine horns and body can be examined via rectal and ultrasound. What are we looking for in these exams?
Pregnancy
Edema
Cysts
Foreign bodies
What structures are examined in the vaginal exam?
cervix
vaginal cavity
Name three diagnostic tests that can be done or submitted to the lab as part of a breeding soundness exam.
Uterine culture
Uterine cytology
Uterine biopsy
The mare has a normal biologic breeding system from late March to ________
Early September
Describe the natural seasonality of the mare.
Dec, Jan, Feb: Anovulatory season
Mar, April: Spring Transition
May-Sep: Natural breeding season
Oct, Nov: Fall Transition
Describe the typical lighting regimen in changing the cycle of the mare.
16 hrs light / 8 hrs darkness
100-200- watt incandescent or two 40-watt fluorescent bulbs = 170 lux
12x12 box stall
45-60 days to promote estrous activity
How does lighting change the estrous cycle: (what happens normally when there are shorter days?)
With shorter days, melatonin is secreted from the pineal gland in the brain.
Melatonin supresses GnRH production from the hypothalamus
Why is GnRH important in the estrous cycle?
GnRH stimulates the anterior pituitary to secrete FSH & LH.
How does lighting change the estrous cycle? (what happens when mares are exposed to more light?)
Longer day length is perceived by pineal gland which decreases melatonin production, so GnRH can be produced to stimlate release of FSH & LH from the anterior pituitary.
________ is produced during follicle growth and causes changes to the uterus, cervix, and vagina.
Estrogen
What happens once ovulation occurs that provides negative feedback to the hypothalamus?
A corpus luteum forms at the site and progesterone is produced.
If conception occurs and a pregnancy begins, progesterone from the ___ will maintain the pregnancy until formation of the _______ _____, which then takes over progesterone production.
CL
Endometrial cup
If conception does not occur, the CL will regress in ___-___ days and a new follicle will begin developing.
14-17
What are three purposes progesterone therapy?
Suppress return to estrus (keep out of heat)
Maintain pregnancy
Part of placentitis regimen
What is the generic name for Regu-Mate
Altrenogest
What route is Regu-Mate (Altrenogest) given, how often?
Oral preparation
Daily, dosed by weight
T/F: Regu-Mate is approved for use in food animals.
FALSE
Regumate may be used as a _______ hormone in embryo transfer
synchronization
Injectable forms of progestin are typically _____ based.
oil
List an example of an injectable progestin product.
Biorelease P4
What is the primary use in prostaglandin therapy?
Lysis of the CL
What are some alternate uses for prostaglandin therpay?
stimulate uterine contractions to control hemorrhage or expel fluid
induce abortion
What are the two common postaglandins?
Lutalyse (food animals)
Prostin (equine)
* Prostin is seldom used, typically just use Lutalyse
What is an off label use of Lutalyse in small animal medicine?
Tx of pyometra in dogs (resolves about 70% of cases)
What are common side effects of prostaglandins?
diarrhea
sweating
mild colic
How are prostaglandins administered?
IM
What is the generic name for Lutalyse and Prostin?
Dinoprost tromethamine
T/F: Lutalyse has no meat or milk withdrawl
TRUE
Compare and contrast Estrumate to dinoprost tromethamine.
Longer half life than DT
less pronounced side effects than DT
Both administered IM
Both are prostagalndins
Both have no meat or milk withdrawl
What is the generic name for Estrumate?
Cloprostenol Sodium
What are the two FDA approved HCG products? What do these products do?
Chorulon
Sucromate (deslorelin)
Stimulate ovulation
Which HCG may be given IV or IM and will induce a follicle >35-38mm to ovulate in 36 hours?
Chorulon
Which ovulatory product is given IM and will induce a follicle > 35mm to ovulate in 48 hours?
Sucromate (deslorelin)
What is the main disadvantage of using Chorulon as opposed to Sucromate?
The mare may develop antibodies and become refractory in response to using Chorulon.
Which ovulatory agent is not FDA approved and only available through a compounding pharmacy in Lexington, KY?
Histrelin
Equidone (domperidone) is an oral paste product used for what?
Fescue toxicosis: only a concern in pregnant mares
Agalactia
Promote early estrus activity
Equidone must be given for ___-___ days to see a response.
5-10
Where can oxytocin come from inside the body?
hypothalamus
ovaries and testes
Uses of oxytocin?
Stimulate milk letdown
Uterine smooth muscle contractions
The estrus stage typically lasts how long? What is this phase also called?
5-7 days (10-12 days in early breeding season)
follicular phase
the estrus period ends with ______.
ovulation
The diestrus period: after ovulation and prior to next estrus is also called what? How long does it last?
luteal phase
lasts about 15 days
During diestrus ____________ is elevated.
progesterone
How long does the embryo stay in the oviduct before entering the uterus?
6-7 days
An initial pregnancy exam can be done at __-__ days. What is the purpose of this exam?
12-14 days
to assess uterine pathology, twins, fluid
When does implantation occur?
day 16-17
When can the fetal heartbeat be observed?
25-30 days post ovulation
What day post ovulation marks the change from "embryo" to "fetus?"
day 40
Endometrial cups form and take over progesterone production at __-__ days.
45-60
Average gestation
338-343
normal can range from 320-380
The rhinopnemonitis vaccine should be administered when during gestation? What are these vaccines called?
3,5,7,9 months.
Prodigy or Pneumabort
The mare should be removed from fescue sources at least ____ months before foaling.
3
What does the pre-foaling Vx include? When should this be done?
Tetanus, EEE, WEE, WNV, Rhino, Flu, Rabies.
2-4 weeks pre foaling to booster anitbody levels in the mare's colostrum
What are signs of impending birth? When do they occur?
Filling of the udder: 2-4 weeks
Distention of teats: 4-6 days
Waxing: 1-4 days
Increase in milk calcium: 1-3 days
Softening and flattening of the croup muscles
Relaxation of the vulva
Three ideal conditions for foaling
Clean
Safe
Quiet
If foaling in a stall, what size is ideal?
14x14'
What bedding is preferred when foaling?
Straw, not shavings
Name some supplies to have on hand for foaling?
Tail wrap
Bucket, soap, towel or cotton
Iodine, betadine or chlorheixidine to dip the naval
Warm fleet enema
The onset of contractions in stage one of labor typically lasts how long?
2-4 hours
During the first phase of labor, the foal is being repositioned to where?
through the cervix and into position in the birth canal.
What event marks the transition from stage one and stage two of labor?
Fetal membranes become visible at the mare's vulva.
Delivery should progress within __-__minutes after the membranes rupture.
10-15
The placenta should be expelled within
1-3 hours
Foal should be born within __-__ mins after the appearance of the allantois; or __-__mins after rupture of the water bag.
30-60 mins; 20-30 mins
The foal should stand and nurse within 2-3 hrs
Naval care and treatment should continue for __-__ days
7-14
What should be checked in the first 24hrs after delivery in the mare?
