• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

Card Range To Study

through

image

Play button

image

Play button

image

Progress

1/440

Click to flip

Use LEFT and RIGHT arrow keys to navigate between flashcards;

Use UP and DOWN arrow keys to flip the card;

H to show hint;

A reads text to speech;

440 Cards in this Set

  • Front
  • Back
normal range length of a nonpregnant cow cycle
18-24 days
proestrus in a cow lasts ___?
3-4 days
PE begins with the completion of ___?
luteolysis
units Progesterone is measured in
nanograms/mL
units estradiol is measured in
picograms/mL
pregnancy recognition in a cow has to happen when?
before end of the luteal phase (day 17)
what happens to LH during PE
baseline concentration increases
LH peak in a cow occurs when?
at the onset of estrus
in a cow, estrogen induces what?
ovulatory surge of LH
in most mammals, ovulation occurs when?
30 hrs after LH peak
how long does the LH surge last in a cow?
8-12 hrs (less than a day)
how long does the progesterone stage last in a cow?
12 days (from day 5 to day 17)
how long does estrus last in a cow?
12-18 hrs
onset of estrus in a cow coincides with what?
the peak of estrogen and LH surge
what happens during estrus in a cow?
-estrogen declines
-clear mucus vaginal discharge
when does ovulation occur in a cow
24-30 hrs after the onset of estrus (after estrus is over)
in the cow, metestrus lasts how long?
3-4 days
metestrus is considered what?
period of the corpus hemorrhagicum (CH) (corpus hemorrhagicum = immature CL)
in what phase is the corpus luteum of a cow not responsive to PGF2a?
during metestrus
what happens after ovulation?
corpus luteum develops
what happens to the hormone levels in a cow when the CL develops?
-low blood concentrations of estradiol
-low LH levels
-slow rise in progesterone (P4)
what is the formal definition of ME?
the period following estrus and ovulation during which the CL achieves mature function (progesterone production)
clinical definition of ME?
the period following ovulation during which the immature CL will not respond to a pharmacological dose of PGF2a by undergoing luteolysis
ME lasts until what day of the cycle?
day 5
what do you see during ME clinically?
bloody vaginal discharge
bleeding during ME comes from where in the cow?
uterus
what is the difference in the uterine bleeding between the cow and the dog?
cow - the bleeding is believed to be due to estrogen withdrawal
dog - proestrus bleeding is due to estrogen stimulation
cow- the luteal phase refers to what part of the cycle?
ME + DE
cow - diestrus is sometimes used as a synonym for what?
luteal phase
DE lasts how long in a cow
from day 4-5 to day 16-18
what happens in a nonpregnant cow around day 16-17?
pulses of PGF2a are secreted by the uterus for approx 36 hrs causing an immediate drop in progesterone concentration
what prevents the PGF2a surge in a cow?
the presence of an embryo
cow - granulosa cells differentiate into what cells?
large luteal cells (LLC)
cow - LLC are ____% steroidogenic but secrete ___% P4
30, 70
cow - true or false: LH is required for LLC progesterone secretion
false - LH is NOT required
cow - what receptors do LLC have and what do they do?
LLCs have most of the PGF2a receptors and produce oxytocin
cow - theca cells differentiate into what?
small luteal cells (SLC)
cow - SLC are ___% steroidogenic and secrete ___% progesterone
70, 30
cow - what is required for maximum progesterone production in SLCs (unlike with LLCs)
LH
cow - progesterone stimulates what?
progesterone receptors and accumulation of phospholipids in uterine epithelium
cow - what does the accumulation of phospholipids in the epithelium of the uterus do?
can liberate arachidonic acid for synthesis and secretion of PGF2a
cow - during the early luteal phase, progesterone and it's receptors block the expression of what?
estrogen receptors and oxytocin receptors (this makes sense bc continual progesterone should mean the animal is pregnant and you don't want the uterine contractions these would cause)
cow - what happens during the early luteal phase?
-the CL develops from the folilcle walls after ovulation
-progesterone stimulates P and it's receptors
-P & it's receptors block both estrogen and oxytocin receptors
cow - what happens during the late luteal phase in a nonpregnant cow?
-long exposure to P downregulates P receptors, increases estrogen receptors, and then increases oxytocin receptors
-oxytocin binds to oxytocin receptors to stimulate prostaglandin secretion
cow - where does the oxytocin come from in the late luteal phase?
the pituitary and CL
cow - where are the oxytocin receptors located?
ont he uterine luminal epithelium and superficial uterine gland duct epithelium
cow - what are the only uterine cells that express COX-2?
the cells with the oxytocin receptors ont he uterine luminal epithelium and superficial uterine gland duct epithelium that secrete prostaglandin
cow - what initiates luteolysis?
endometrial PGF2a secretion
cow - when does uterine venous PGF2a increase?
days 16-17 of PE
cow - what can happen to the normal cycle if PGF2a is given during DE (day 6-17)?
shortened
cow - how does PGF2a reacht he ovaries?
ipsilateral route
cow - what happens when you give PGF2a when you have a mature CL?
causes luteolysis and the onset of PE (follicular phase), leading to estrus and ovulation in 3-4 days
cow - if PGF2a is given to a group of cows, which will respond?
only those in DE
cow - after the first dose of PGF2a, how long will it take for the cows to all be in DE?
11 days
cow - what will happen after the 2nd shot of PGF2a? all at the same time?
all the cows will come into estrus together in 3-5 days
-not at exactly the same time (it will be timed so that most can be bred w/i a 2 days period)
cow - in a nonpregnant cow, how does PGF2a from the uterus reach the ovary and CL?
via the ipsilateral uterine vein and ovarian artery
cow - hysterectomy early after ovulation prevents what?
luteolysis
cow - what 3 things delay luteolysis?
-removal of the uterine horn ipsilateral to the ovary that contains the CL
-destruction of the endometrium
-ligation of the uterine vein ipsilateral to the ovary that contains the CL
cow - source of luteolysin and the route to the CL
endometrium, local/ipsilateral via uterine vein
in which spp is PGF2a NOT transferred from the uterine v to the uterine a (bc they are wrapped together) - cow, mare, sow, ewe?
mare
cow - is the influx of PGF2a to the CL rapid or slow?
rapid
mare - how does PGF2a reach the ovary?
systemic route
mare - how much PGF2a is needed to cause luteolysis?
only 1mg given IM
what hoofed spp is most sensitive to PGF2a?
mare
cow - how many mg of PGF2a is required in the cow for luteolysis?
25mg IM
in most spp, where is PGF2a destroyed?
by one pass through the lungs
what is the "maternal recognition of pregnancy?"
the physiological process whereby the conceptus signals its presence to the maternal system and prolongs the lifespan of the CL (prevents PGF2a)
cow - what do we believe to be the recognition of pregnancy?
the conceptus elongates from a spherical --> tubular and then --> filamentous form to contact the entire lumen of the uterus and produce interferon-tau which prevents development of the luteolytic mechanism
cow - at what point must the embryo by in the uterine horn to prevent luteolysis? what horn?
-day 16 post estrus
-ipsilateral to the ovary that contains the CL
cow - what is the pregnancy recognition signal secreted by the elongating conceptus? what does it act on?
-interferon-tau
-the endometrium to suppress PGF2a release
cow - what are the cells that synthesoze and secrete IFN-tau?
conceptus trophectoderm (the cells on the outside of the fetus)
possible mechanisms for IFN-tau in ruminants
-suppresses transciption of estrogen receptors thought to be necessary for expression of oxytocin receptors OR IFN-tau directly inhibits oxytocin receptor expression --> prevents endometrium from releasing luteolytic PGF2a pulses
-IFN-tau my steer prostaglandin metabolism towards PGE rather than PGF2a (downregulate enzymes that convert PGE to PGF2a during early pregnancy)
PGF2a is derived from ___? produced in ___?
-arachidonic acid
-the uterus
LH - large or small molecule that comes from where?
-large molecule
-comes from the pituitary
progesterone - what is it and where is it produced? How is it used sometimes?
-steroid
-produced by the CL, placenta, and all steroid producing tissues
-pathway for prod'n of most steroids
estrogen - what is it and where is it produces?
-steroid
-ovary and many other steroid producing tissues
oxytocin - what is it, where is is produced, and where is it stored/released from?
-peptide fragment
-produced from neurosecretory cells of the hypothalamus
-stored/released from the posterior lobe of the pituitary (and by the CL in the cow)
cow ovary - what will you find on palpation during PE?
Cl will be regressing (feels harder than developing follicles
cow ovary - what will you find on palpation during estrus?
-CL regressed further and probably non-palpable
-soft follicles
cow ovary - what will you find on palpation during early DE?
-early CL feels soft and roughened
-regressed CL non-palpable
-wave of follicles to day 5 then atresia at days 10-11
cow ovary - what will you find on palpation during mid-late DE?
-CL usually easily palpable (can be 25% errors in detection
-no significant follicles
cow uterus - what will you find on palpation during PE?
tone developing
cow uterus - what will you find on palpation during estrus?
-marked tone (esp heifers)
-engorged uterus
cow uterus - what will you find on palpation during early DE?
tone declining as edema reduces
cow uterus - what will you find on palpation during mid-late DE?
-no significant tone
-flaccid uterus
cow cervix - what will you find on palpation during estrus?
-open external os
-congested and edematous
cow cervix - what will you find on palpation during mid-late DE?
closed
cow vagina - what will you find visually during PE?
-hyperemia
-some "tacky" mucus
cow vagina - what will you find visually during estrus?
-congested, edematous mucosa
-smooth, glassy mucus: "Bulling string"
cow vagina - what will you find visually during early DE?
-little mucus
-ME bleeding in heifers and some cows
cow vagina - what will you find visually during mid-late DE?
pale
cow vulva - what will you find visually during PE?
slight swelling (not really noticeable)
cow vulva - what will you find visually during estrus>
swollen, soft
cow vulva - what will you find visually during early DE?
-perhaps dried mucus
-signs of mounting on rump of cow
cow - what behaviors will you see during PE?
none
cow - what behaviors will you see during estrus?
-restlessness
-tail swishing
-vocalisation
-mounting and standing to be mounted
cow - what behaviors will you see during mid-late DE?
none
cow - what hormone changes will you see during PE?
-falling progesterone
-rising estradiol
cow - what hormone changes will you see during estrus?
estrogens
cow - what hormone changes will you see during early DE?
rising progesterone
cow - what hormone changes will you see during mid-late DE?
plateau of progesterone
Lutalyse is a brand name for what?
Dinoprost Tromethamine - a native PGF2i
if "prost" is in a generic name, what will most likely be the drug?
a prostaglandin
Name 3 other prostaglandin products
-estrumate (cloprostinol - synthetic analog)
-bovilene (fenprostalene) - synthetic analog
-prostamate (dinoprost tromethamine)
what are prostaglandins used for in veterinary medicine?
-luteolysis (shortens duration of DE)
-abortion (via luteolysis)
-treatment of pyo-, muco-, or hydrometras (via luteolysis) in a cow
-induction of parturition (cow & sow)
what safety issues are there with handling prostaglandins?
no women of child bearing age should handle prostaglandin bc of a possible interference with pregnancy
luteolysis in a mare is called?
short cycling
if used for abortion, when should prostaglandins be given?
before day 35 (don't work well after that)
what structure is GnRH , where is it produced, where is it transported, and what does it do there?
-decapeptide produced in the hypothalamus and transported to the pituitary gland where it stimulates FSH and LH release
what is the most common use in veterinary medicine for GnRH?
To induce ovulation or erlease LH for luteinization of follicles and luteotrophic effects
true or false: GnRH is identical in all mammals?
true
name the 6 functions of GnRH
-stimulate the release of FSH/LH
-initiate and maintain follicular growth (via FHS/LH)
-stimulate ovulation
-act as a luteotrophic agent
-maintain spermatogenesis and angroden levels (via LH)
-as a drug, downregulation of gonadotrophin release
what does GnRH treat?
cystic ovarian disease
what does GnRH stimulate/help with?
-stimulates follicular development (breeding management)
-stimulates ovulations to match breedings by AI
-aid in causing additional ovulations and maintenance of the CL for timed AI (so PGF2a can be used effectively)
-increase spermatogenesis and libido in males
Common drug used for commercial GnRH
Cystorelin (a Gonadorelin - natural mammalian GnRH)
other GnRh products
-Gonadorelin (Cystorelin & Factrel)
=buserelin (receptal)
-Desorelin (Ovuplant)
-Leuprolide (Lupron - neoplasia in ferrets)
What is the structure of oxytocin?
peptide composed of nine amino acids
where is oxytocin synthesized?
hypothalamus, as well as the CL and endometrium
where is oxytocin transported, stored, and released?
it is transported to the posterior pituitary, stored in the Herring Bodies there, and released into the general circulation from nerve terminals
what will and overdose of oxytocin cause?
antidiuretic effect
what does oxytocin do?
causes myometrial contractions, milk let-down, participates in luteolysis, and influences social, sexual, and maternal behavior
what is oxytocin used for?
-stimulate uterine contractions during parturition
-empty uterus of fluid after parturition
-initiate parturition (esp in equine)
-stimulate milk let-down (esp in sows)
-dystocia
-stimulate sexual arousal and cause passage of sperm accumulation blocking the ampulla in males (mainly equine)
where is oxytocin stored?
Herring Bodies in the pituitary gland
what is oxytocin used for in a horse?
induction of parturition
two good things about generic oxytocin products
inexpensive and good shelf life
3 generic brands of oxytocin
oxytocin, vetocin, and pitocin
what are two key hormones that influence pair bonding and monogamy in some species?
oxytocin and vasopressin
which hormone influences female monogamy?
oxytocin
which hormone stimulates male monogamy?
vasopressin
how many carbons does testosterone have?
19
how many cabrons does progesterone have?
21
how many carbons does estradiol (E2B) have?
18
can estrogen be metabolized to progesterone?
no
can progesterone (P4) be metabolized to estrogen?
yes
what is the pathway from cholesterol to estradiol?
choloesterol --> pregnenolone --> progesterone --> testosterone --> estradiol
drugs with "gest" in them are usually what type of hormone?
progesterone ("gest"ation)
why are there so many synthetic oral progesterone?
bc natural progesterone does not build up an effective systemic concentration when administered orally
name two synthetic oral progesterones and tell what each drug is used for in which spp
1. Megastrol acetate: Ovaban (dog)
-used to postpone estrus
-used in cats for dermatological conditions
2. Regu-Mate (altrenogest; allyl trenbolone) (horse, pig)
what is a brand name for medroxyprogesterone acetate, what is it, and why is it no longer used in dogs in the USA? In what spp is it used and for what?
-Depo-Provera, a synthetic injectable progesterone, and bc it gives dogs pyometra
-used in cats for behavior modification
how often is natural injectable progesterone given?
every day when a 10-14 day effect is desired
what are the uses for progesterone?
-mimic luteal phase
-contraception
-support pregnancy when P4 deficiency is suspected
-induced lactation in dairy cows: combination of drugs
how is progesterone mimicking the luteal phase helpful?
delays heat, synchronizes estrus, and treats anestrus, cystic ovarian dz, and puberty
hwo does progesterone act as contraception?
delays estrus (or prevents ovulation in humans - birth control pills)
what combination of drugs induces lactation?
P4, estradiol, dexamethasone, and reserpine
where are estrogens produced?
the ovarian follicle and placenta
what happens in the absence of progesterones?
estrogens cause estrus behavior in females, changes int he uterus and vagina
what do peaks of estrogen concentration during estrus cause?
release of GnRH and LH leading to ovulation
what are estrogens used for?
to precipitate the release of GnRH, LH, and prostaglandin, to mimic estrus, to replace estrogen when deficiency is suspected, and to terminate pregnancy
what two drugs are usually combined to form birth control pills?
estrogen and progestin
what is DES?
diethylstilbestrol - a non-steroidal estrogen
how are many racing dogs kept out of heat?
doses of testosterone
true or false: giving testosterone/androgens to racing dogs is one of teh safer ways to keep a dog out of heat?
yes
what happens when a dog who has been given androgens to delay heat is taken off the androgen?
never know when the dog will come into heat again: could be 2 weeks, could be 2 years.
what is the more androgenically active form of testosterone in male organs?
dihydrotestosterone (a hormone produces by 5a-reductase acting on testosterone)
what are testosterone and androgen drugs used for?
suppress estrus, enhance libido (teaser animals), and replace testosterone when deficiency is suspected
what else do androgens do? (hint: think sports)
enhance muscle growth and speed recovery from injury
when given in its natural form, testosterone is usually linked to what?
an ester
3 forms of injectable testosterone
cypionate, enanthate, and propionate
name 4 ways testosterone is used in vet medicine.
-to make teaser cows/steers for estrus detection - testosterone ester given as an initial loading dose and re-administer every 10-14 days
-keep racing Greyhound femals out of heat - give methyl-testosterone orally 2x/wk or testosterone ester IM 1x/2wk
-testosterone-responsive urinary incontinence in castrated dogs
-can help avoid uterine dz or mammary tumors
basically every racing greyhound hs been given what to keep them out of heat?
androgen
neurosteroids
metabolites that are still active, produced in the brain
one of the main modulators (the gabba receptor in the brain)
allopregnenolone (metabolite of progesterone)
neuroactive steroids
act instantaneously as a neurotransmitter -
what is 3a-androstenol?
a neurosteroid that is basically a pheromone produced by many mammals. it is an immobilizer and hypnotic
most common form of estrogen
birth control pills
what is ECP and what was is used for?
an injectable estrogen (estradiol cypionate) - was used in cattle for uterine infection or pyometra --> while fixing some things, it prolongs other conditions
what is synchro-mate B?
used to synchronize cattle
-a progestin with some estrogen in it
when are estrogens used?
whenever we want to enhance heat signs (abortion, luteolysis, etc)
-mismate injection (dog/cat)
-enhance uterine motility and clearance of uterine infection, esp cattle (can incr. uterine pathology in dog)
-enhance estrus expression
-tx urinary incontinence in spayed dogs & cats (DES)
-cause luteolysis and abortion (cow though prostaglandin is better)
-initiate PE and estrus in dog (can mimic the slow progression)
problem with using estrogens in dogs
-overdose can cause bone marrow suppression (it is severely toxic)
-high risk of uterine pathology
Name 2 reasons the use of estrogens has been decreasing over time
-questionable efficacy in reproductive tx
-availability of more specific drugs to treat conditions
most important single fact to remember about estrogens
can be very toxic in dogs
true or false: LH and FSH have the same structure in all spp
false: they differ somewhat
what type of molecule is FSH?
a large protein molecule w/ alpha and beta subunits
true or false: the beta subunit is the same between FSH, LH, and TSH
false: the alpha subunit is the same between FSH, LH, and TSH. the beta subunit determines the activity
where is FSH produced?
the anterior pituitary
secretion of FSH is inhibited by ___?
inhibin-A and inhibin-B
secretion of FSH is augmented by ___?
activin
follistatin controls ___?
activin and inhibin activity
what are the two functions of FSH?
-initiates maturation of pre-antral follicles
-initiates Sertoli cell function for spermatogenesis
What do we use FSH for in vet med?
-stimulate ovarian function
-superovulation for ambryo transfer
-promote spermatogenesis
true or false: FSH use if limited in vet med
true: when looking for the FSH affect, we usually choose another type of drug rather than FSH itself
FSH, LH, hCG, and eCG are produced by what tissue?
chorionic tissue
true or false: FSH, LH, hCG, and eCG are all small molecules
false: they're all large molecules
main hormone for detecting pregnancy
eCG ? detecting the presence of fetal membranes
eCG used to be called ___?
PMS: pregnant mare serum
main hormone for detecting pregnancy in dogs?
relaxin
what is FSH used for in human medicine?
-assisted reproduction (superovulation)
-polycystic ovary syndrome (ovulation)
what does LH do?
acts on follicles to cause oocyte activation, ovulation, and luteinization
how does LH stimulate testosterone prod'n
through Leydig cells
traditional pharmeceutical products w/LH activity have been made from ___?
pituitary glands and pregnant human urine
LH drugs are used for ___?
-tx of follicular cysts
-induction of ovulation
what type of molecule is LH?
glycoprotein
where can you get an LH assay?
only available in specialized labs
what do you use a canine in house assay for?
it is semi-quantitative, available for timing AI
true or false: LH assays are routinely run in cattle and swine
false
what is special about the recombinant LH hormone on the market?
the recombinant is the only one that is single strand
where is LH produced?
anterior pituitary
what inhibits the release of LH?
low concentrations of P & E
what stimulates the release of LH?
estrogen spike
where does LH bind? what does it do there?
-to receptors on follicles, CL, and Leydig cells
-stimulates the production of steroids using these cells
function of LH
-stim progesterone prod'n by CL
-stim testosterone prod'n by testis
-stim. ovulation
-activated pre-ovulatory oocyte
-involved in puberty and seasonal cycles
what is LH used for in mares?
to induce ovulation
what is LH used for in cows? is this common?
to tx cystic ovarian disorder
-not common, but recombinant form is NOT used
name some products used in vet med that have LH activity
-hCG: horses
-pituitary extracts (but not much since GnRH is available)
name the LH product used by male athletes as a bidy-builder
Pregnyl
What hormone does the equine placenta produce with LH activity?
eCG (Equine Chorionic Gonadotrophin)
eCG was formerly known as ___?
PMS or PMSG (Pregnant Mare Serum Gonadotrophin)
when is eCG used in other animals?
when FSH effects are desired bc it has strong FSH activity in animals other than the horse
what hormone are you testing for when testing for pregnancy in the mare?
eCG
what does eCG do during pregnancy?
-stim luteinization of follicles
-maintain CL activity
0promote production of progestins
in spp other than the horse, what is eCG used for?
-stim follicular development
-shorten anestrus
-induce ovulation
-superovulation
what type of molecule is eCG?
glycoprotein w/an amino acid sequence identical to eLH - beta subunit is coded by the same gene as eLHbeta
true or false: the molecule for eCG is the same as LH
false: bc they are produced by different cells, the molecules are different but the amino acid sequence is the same
true or false: eCG has a longer circulating halflife the LH
true
eCG is extracted from what?
the serum of pregnant mares
true or false: eCG has FSH-like activity in all spp
false: eCG has LH-like activity in all other spp EXCEPT the horse
mainy activity of eCG in the mare
LH-like activity (luteinization)
what is eCG used for in pigs?
to reduce post-partum anestrus
what is eCG used for in small ruminants?
to increase ovulation rate
what is eCG used for in dogs?
to induce estrus
what is eCG used for in exotic mammals?
induce estrus
what is eCG used for in cattle?
superovulation
what is eCG used for?
induction of puberty
what is PG600?
a combination of eCG and hCG
where can you get generic PMSG?
either from a chemical supplier (comes as a biochemical) or from a drug company (as a pharmeceutical agent) - can buy a powder and formulate your own
name the gonadotrophin produced by the human placenta that has FSh and LH activity
hCG: human chorionic gonadotrophin
when is hCG used?
when LH affects are desired
what does hCG do during human pregnancy?
-maintain CL activity
-promote the prod'n of progestins
how is hCG used in mares?
used for timed ovulation
how is hCG used in cattle?
used to treat cystic ovarian disease
what are you testing for with OTC pregnancy tests in women?
hCG
hCG is what type of molecule?
has an alpha-subunity that consists of 92 amino acid residues and is encoded by a single gene
the LH/hCGbeta gene cluster has what?
one LHbeta gene and 6 hCGbeta genes
what is hCG used for?
used extensively in all domestic spp to induce ovulation
hCG works particularly well in what spp?
horse
what happens with repeated use of hCG int he same animal?
-may result in reduced effectiveness w/the later administrations
-has the potential to trigger reactions in animals that have received it previously
problems with FSH, LH, hCG, and eCG
create special problems in manufacture, handling, storage, and biological response bc of their type, size (large), and origin
-degrade rapidly if kept in soln at room temperature (typically lyophilized or frozen)
-capable of generating an immune response (Ab response at minimum)
-repeated use may result in reduced effectiveness
purity of preparation of FSH, LH, eCG, and hCG is in question because ___?
these products are derived from animal tissue or blood and there is a possibility of the presence of other biologically active substances or infectious agents
dog - which dog breed(s) have a single annual seasonal ovulation (ovulate once a year)
Basenji and wild canids
which dogs have a cirannual prolactin rhythm?
dogs housed outdoors
dog - when do coyotes and wolves breed?
in the spring in the northern hemisphere
dog - when will you find bloody vaginal discharge?
first day of PE
dog - what marks the beginning of anestrus?
P4 returning to basal levels
dog - how long should anestrus in a dog be to promote normal fertility at the subsequent estrus?
a couple of months (usually 4-5)
dog - when is anestrus?
from the end of the luteal phase (or pregnancy) to the beginning of PE
dog - what does anestrus look like?
it is the quiescent phase of the cycle, behaviorly and clinically
dog - what is the level of P4 at anestrus (numbers)?
1-2ng/mL
dog - what happens during the last two months of AE before estrus?
FSH and estrogens rise
dog - what is included in the interestrus interval and how long does it last?
-anestrus and the luteal phase
-6-7 months
dog - how many times does estrus occur?
slightly less than 2xs annually
dog - what influences the interestrus interval?
breed
-SLIGHT trend: the bigger the dog, the longer the interestrus interval (exceptions: GSD, rott, basset, cocker, lab)
dog - interestrus intervals are shrinking in what breed?
german shepherd
dog - minimum normal interestrus - why?
4 months - endometrium needs time after the luteal phase for repair
dog - if interestrus is less than 4 months?
tends to result in infertility
dog - what may be needed for maintaining the length of anestrus?
prolactin (prolactin suppressors shorten AE)
dog - average length of PE
9 days
dog - what is PE usually defined by?
blood passing from swollen vulva (bloody discharge)
dog - what is the behavior during PE?
may attract males but is NOT receptive to mating
dog - what happens endocrinologically during PE?
-estrogen peak rises before estrus begins
-FSH has already decreased
-P4 starts rising when LH peak begins
-increasing percentage of "superficial" cells in vaginal cytology
dog - what happens behaviorly during PE?
increasing likelihood of observing sexual reflexes seen in estrus
-winking vulva
-stance in response to stimulation of the vulva
-"flagging" of tail
dog - average duration of estrus
9 days
dog - behavior during estrus
standing to be mounted
dog - what does the discharge during estrus look like?
less bloody than PE
dog - what happens endocrinologically during estrus and what does it cause?
-rising P4 and LH peak seems to cause more receptivity to male
-LH peak used to define first day
dog - what defines the first day of estrus endocrinologically? is this correct?
LH peak
-onset can actually be from 3-5 days after LH peak
-temperament of male and female may cause variation
dog - what does a vaginal smear look like with a dog in estrus?
-greater than or equal to 90% superficial cells (cornification)
-
dog - when does cytological estrus start in relation to the LH peak?
can range from 6 days before to 4 days after the LH peak
dog - how long might the LH surge last?
24-96 hrs
dog - how long after the LH surge does ovulation occur?
2-3 days
dog - oocytes are ovulated as what?
primary oocytes
dog - when does fertilization take place in relation to PE, estrus, LH peak, etc?
-after the first meiotic division
-48-72 hrs after ovulation
-5-6 days after first day of estrus and LH
-13-15 days after first day of PE
dog - when are single matings fertile?
anytime in the first half of estrus
dog - how long can spermatozoa live in the uterus during estrus?
7-8 days
dog - what do you get with good timing of insemination?
higher fertility
-higher percentage of conception rate
-larger litter size
dog - when does vaginal cytology change to parabasal cells?
8-9 days after LH
dog - what does a vaginal cytology smear show 8-9 days after LH?
parabasal cells
dog - do females still stand for mating 8-9 days after LH?
yes
dog - is fertility high or low after parabasal cells appear?
low
true or false: the luteolysis mechanism in canines is similar to the mechanism in hoofed animals
false: there is not mechanism for luteolysis
dog - the first day of cytological DE usually occurs when?
when the female is still in estrus
true or false: in the dog, false pregnancy is not considered a disease
true
dog - length of DE
approximately the length of gestation
dog - when does the luteal phase begin
ovulation
dog - when is the P4 elevated?
before ovulation (with LH)
dog - when does the early luteal phase take place?
during estrus
dog - true or false: estrus and ME happen at the same time
true: estrogen rises and the CL starts developing to maturity at the same time
dog - what happens on the first day of cytological DE?
-sharp decr in % of superficial cells, incr in parabasal cells
-P4 is elevated so chance of conception is greatly reduced
-5-7 days post ovulation
dog - cytological DE can be used for what?
-retrospectively to evaluate timing of breeding
-to predict day of whelping (in 57 days)
dog - when does progesterone peak?
-30 days after LH surge
dog - when does progesterone decline?
gradually for 5-6 weeks
dog - true or false: P4 profile is similar in pregnant, unmated, and hysterectomized animals?
true
dog - when do LH and prolactin increase?
during 2nd half of DE
dog - what is one main hormone difference in pregnant and nonpregnant dogs?
relaxin - high in pregnant
dog - where does relaxin come from?
primarily of placental origin
dog - define galactorrhea
false pregnancy or pseudopregnancy
dog - when does galactorrhea commonly occur?
at end of luteal phase
dog - list out the typical/idealized estrus
-PE lasts 9 days
-estrogen peak and LH peak are close to the 1st day of estrus
-ovulation: 3rd day of estrus
-oocytes ready to be fertilized on 5th day of estrus
-breedings anywhere from day 1 to day 6 of estrus (or day 10-15 after PE bleeding is first noticed) - results in high conception rate (~90%)
-2 breedings separated by 2 days anytime in the first week of estrus - likely to be successful if both male and female are normal
dog - what do you do if the bitch won't bleed?
requires starting smears on a weekly basis
dog - in normal matings, how long is the period of potential fertility?
10 days
dog - when is the period of high fertility?
from the day before the LH surge to 6 days after
dog - the ideal piece of info for breeding managment
LH
dog - an accurate method for determining breeding times
peripheral plasma concentration of LH
dog - two tests used to determine peripheral plasma concentration of LH
-radioimmuniassay (impractical)
-ELIZA
dog - why is it important to know when the LH peak is when doing AI with frozen semen?
the peak doesn't stay around lone and there is a 24hr window to hit
dog - why is the RIA test for LH impractical?
turnaround takes too long
dog - what does the ELIZA test for LH do? what does it require?
-can identify LH surge w/i 1-2 days
-usually requires a daily sampling
dog - decr in estrogen and progesterone often mean what for LH?
incr in LH
dog - how is P4 used to determine LH surge time?
P4 concentration exceed 2ng/mL the day of or after LH surge
dog - when breedings require critical timing (AI), when can they be performed?
one day after P4 exceeds 8-10ng/mL
dog - what does it usually mean when P4 exceeds 8-10ng/mL?
these values are typically seen the first day of oocyte readiness for fertilization
dog - what are two tests available for P4 concentration evaluation?
RIA and ELIZA
dog - which is better, RIA for P4 or LH?
P4 - fast turnaround
dog - what is the breeding time for normal dogs using LH and P4?
-day of LH surge to 5 days after
-day P4 exceeds 2ng/mL to 4 days after
dog - what is the breeding time for dogs requiring critical timing using LH and P4?
-4 or 5 days after LH surge
-3 days after P4 exceeds 2ng/mL or 1 day after P4 exceeds 8-10 ng/mL
dog - estrogens/estradiol is ___ during late PE, and ___ during estrus?

true or false: estrogens are considered a practical assay for determining LH surge
elevated, not-elevated

false
dog - true or false: U/S imaging is a well-developed technique for use in determining timing of breeding
false: no well developed for use in general practice, but you could potentially observe ovulation (follicles to CL)
dog - 2 diseases to test for
-brucella canis
-canine herpesvirus
dog - how do you test for B. canis?
serology (NOT culture) is the best
dog - true or false: want all dogs to be sero(-) for canine herpesvirus
false: all dogs should be exposed bc at some point bc it's hard to quarantine them during pregnancy or breeding
dog - if the female has a negative herpes titer, what does it mean? how do you handle it?
-the female is susceptible
-isolate her the last 3 weeks of gestation and the first 3 weeks following whelping
dog - true or false: most bitches will have a positive culture for some bacteria
true: it's NORMAL
dog - true of false: there is no uniformity between the bacteria cultures of dogs in the same kennel/household
false
dog - name some of the typical aerobic isolates you'll see in a vaginal bacterial culture
-E. coli
-coagulase (+) & (-) Staph
-a-hemolytic & B-hemolytic strep
-pasteurella
-proteus
-bacillus
dog - true or false: sperm is produced throughout the entire ~20 minute ejaculation
false: all the sperm is produced w/i the first few minutes
dog - is the whole ejaculate used in AI or just the sperm-rich fraction?
the whole ejaculate, though it can be diluted to 4-5cc with prostatic fluid
dog - where is the semen deposited in AI?
the fornix of the vagina
dog - how long can chilled semen be transported for AI?
up to 48 hrs in semen extender
dog - how does frozen semen present?
in pellets or straws
dog - two techniques for AI with frozen semen
-transcervical (skandinavian technique)
-surgical - semen is injected by nedle and syringe into lumen of uterine body and horns
dog - at what day of a pregnancy will you be able to see spines/skulls on an x-ray (aka when do the bones calcify)?
day 45
dog - what does oxytocin induce in a horse?
parturition
dog - how long past ovulation does estrus often last?
1 week
dog - what does this coincide with in other animals?
metestrus
dog - what happens to estrogen and P4 during most of estrus?
estrogen is low, P4 is rising
dog - at what point can the thick layer of superficial cells in the vaginal epithelium no longer be supported?
8-9 days post-LH peak
dog - what happens cytologicall in late strus?
superficial cells are lost and parabasal/intermediate cells predominate
dog - why are there no neutrophils/polymorphonuclear cells in a vaginal smear during most of estrus?
superficial cells (cornified layer) prevent them from entering the lumen
dog - why are PMNs/neutrophils in the smear during the end of estrus?
with the loss of the dead cell layer (superficial cells), they can now migrate thru the epithelium to kill bacteria
dog - estrus is defined by ___?
behavior - some dogs start standing well before LH or estrogen peaks (some dogs continue standing for 10-12 days after LH peak while others refuse to stand after less than a week post-LH)
dog - days with the highest conception rate
days 4* and 5 before DE (closer to DE)
dog - groups of days with the highest conception rate
from days 4-10 before day 1 of cytological DE
dog - canine sperm can live for how long in the estrus canine uterus?
1 week
dog - optimum fertilization/survival rate for single matings occur when?
4 days before cytological DE
-aka 5 days after LH peak
dog - conception rate is still over 90% how many days after LH peak
6
dog - conception rate is over 90% for a period of how many days? when does this period being?
-8 days
-begins 10 days before cytological DE (aka the day before LH peak)
dog - when does fertilization rate of oocytes w/embryo survival peak?
4 days before day 1 of cytological DE
dog - true or false: after fertilization rate peaks 4 days before cytological DE begins, the rate stays high for another few days before dropping
false: there is a rapid reduction of fertility rate one day later (3 days before DE)
dog - true or false: gestation begins with breeding
false: gestation begins with fertilization
dog - why are whelpings groups closely around 57 days of DE (or 64-66 days after LH peak)?
bc fertilization is presumed to be about 4 days before DE
dog - when marked against LH peak of day 1 of cytological DE, small litters have short or long gestation lengths?
long
dog - when marked against LH peak or day 1 of cytological DE, large litters have short or long gestation lengths?
short
dog - pregnancy and non-pregnancy pattern are similar for what hormone? what is the one exception?
-progesterone
-exception: the abrupt decline just before parturition
dog - what is the difference between non-pregnancy and pregnant total estrogens?
-nonpregnant: constant during DE
-pregnant: elevated last 3 weeks of pregnancy
dog - what estrogen is higher in non-pregnant dogs than in pregnant?
estradial-17B
dog - which estrogen is higher in pregnant than in non-pregnant dogs?
estrone
dog - where is relaxing produced?
placenta (possibly ovaries and uterus
dog - in what phase/animals is relaxin not detectable?
-males
-nonpregnant DE
-anestrus
dog - when does relaxin peak in pregnant females?
2-3 weeks before parturition
dog - is prolactin low or high during DE?
low in nonpregnant
dog - when is prolactin elevated?
late pregnancy and lactation
dog - when does LH increase?
in the late luteal phase
dog - true or false: LH increases in the late luteal phase of pregnant animals but not in non-pregnant
false: it increases in the late luteal phase of both pregnant and non-pregnant animals
dog - at what day is there a difference between pregnant and non-pregnant concentrations of FSH?
day 16 following the LH surge
dog - after day 16 following the LH surge, what is the FSH concentration difference between pregnant and non-pregnant bitches?
there are higher concentrations of FSH in pregnant vs non-pregnant
dog - when can you dx pregnancy with abdominal palpation?
days 25-35 post-breeding
dog - when can you see fetal calcification on radiographic imaging?
43-46 days after LH peak
dog - when can you first observe pregnancy on an ultrasound?
20 days after LH peak
dog - what do you see on an ultrasound 20 days after LH peak?
fluid-filled vesicle
dog - around what day of gestation can fibrinogen be used to detect pregnancy? at what concentration?
-21-30 days
-greater than 250mg/dl
dog - at what concentration is fibrinogen considered a 98% accuracy? at what point is it considered 100%?
- >280mg/dl
- >300mg/dl
dog - why is fibrinogen a test used to detect pregnancy? is it used often?
-bc fibrinogen (or acute-phase proteins) incr with inflammation
-not often used
dog - when does relaxin rise?
at 20-30 days of gestation
dog - what test can be used to detect relaxin? when can it be used? what do you do if it's negative?
-ELISA (ReproCHEK)
-after 21 days of gestation
-recheck negatives in 7-10 days
dog - what happens to hormones in initiation of parturition?
-fetal ACTH incr
-fetal adrenal cortisol incr
-estrogen incr
-PGF2a incr
-progesterone dec
-oxytocin incr
dog - true or false: oxytocin can either initiate or assist in parturition in the dog?
false: oxytocin is used to assist in parturition but NOT to initiate
dog - true or false: there is no palpable difference between pregnancy and pseudopregnancy
true
dog - why is induction of parturition rarely done in a dog?
there's rarely call for it
dog - name three drugs that can be used to induce parturition in a bitch
-glucocorticoids
-prostaglandins
-oxytocin
dog - what glucocorticoid is used to induce parturition? when is it used? what happens to the pups?
-Dexamethasone
--prior to 51 days - pups born alive and die
--at 57-58 days, parenterally causes parturition in 1-2 days
dog - what are prostaglandins mostly used for?
inducing luteolysis - not really studied for the purpose or parturition
dog - in what breed is oxytocin used for mostly?
parturition in the mare - not really studied in the dog
dog - what is considered a prolonged gestation?
over 65 days after ovulation
dog - normal gestation length
57-72 days
dog - all bitches more than ___ days POSTBREEDING is considered prolonged
72
dog - with known day of CYTOLOGICAL DE, normal carrying is ___ days. what is considered prolonged?
-57
-60
dog - the known level of what hormone during estrus changes the "normal" gestation period?
P4
dog - what is the normal gestation period of a bitch whose P4 levels were between 1-1.9ng/mL during estrus?
65 days
dog - what is the normal gestation period of a bitch whose P4 levels were between 2-3.9ng/mL during estrus?
64 days
dog - what is the normal gestation period of a bitch whose P4 levels were between 4-10ng/mL during estrus?
62-63 days
dog - what is true about the correlation between P4 levels during estrus and gestation period?
the higher the P4 levels during estrus, the shorter the gestation period
dog - small litters are often associated with ___?
dystocia and prolonged gestation
dog - dystocia can be associated with ___?
small litters and singletons
dog - when is a litter considered "overdue?"
with delayed parturition more than 24 hrs beyond temperature drop
dog - what are some ways to assess the normality vs abnormality of gestation period?
pseudopregnancy vs pregnancy, known P4 levels during estrus, known day of cytological DE, singletons or small litter size, delayed parturition after temperature drop, primary uterine inertia due to oversized litter
dog - what is the MOA of steroids
presumed negative feedback on pituitary and hypothalamus, suppressing estrus byt GnRH, FSH, and LH release
dog - what do progestins do?
mimic luteal phase and prevent estrus
dog - what is Promone and what is the problem with it?
progestin (Depo provera), injectable medroxyprogesterone
-caused pyometras
dog - what is Ovaban? when is it given?
megestrol acetate, oral progestin
-only progestin approved for estrus suppression
-also used to suppress concurrent PE
-given once daily
dog - what is the only progestin approved for estrus suppression?
Ovaban
dog - How long is Ovaban approved for? future problem?
32 days
-don't give it to dogs you want to breed
dog - what is medroxyprogesterone acetate? when is it given? what are the problems with it?
-long acting progestin
-given every 3-6 months (DURING ANESTRUS)
-elevated urterine and mammary dz, return to estrus is variable (1.5-26 months)
dog - what is Proligestone? when is it given? what is the efficacy?
SQ progestin
-given every 5 months (DURING ANESTRUS)
-95-99%
dog - what two progestins must be given during anestrus?
proligestrong & medroxyprogesterone acetate (both used outside the US)
dog - what is the only androgen approved in the US for contraception? oral in injectable?
Cheque drops (mibolerone)
-oral
dog - what is mibolerone? what is it used for?
aka cheque drops
-androgen approved for contraception in dogs
-to keep dogs out of heat if coming into heat too often (long AE & PE)
dog - what is most often given to female racing greyhounds to keep them from coming into heat?
oral and injectable forms of testosterone
dog - testosterone proprionate is used for? how often is it given?
injectable - racing greyhounds to keep them out of heat
-once every 2 weeks
dog - what is methyltestosterone and what is it used for? when is it given?
oral testosterone given to female racing greyhounds to keep them out of heat
-given twice a week
dog - safest and most reliable steroids used for contraception
testosterone/androgens
dog - what hormone is the basis for the "morning after' pill?
estrogens
dog - when estrogens are used for early termination pregnancy, they are aka ___?
mis-mate shot
dog - MOA of estrogens
-movement of ova through oviduct is impaired
-delays uterine gland prod'n of proteins necessary for embryo survival (normally P4 would be the main steroid influencing uterine fn)
-impairs implantation
dog - side effects of giving estrogens for pregnancy termination
-overdose could cause bone marrow suppression
-CEH and pyometra are long-term effects on uterus
dog - what estrogen products are approved for pregnancy termination?
none
dog - what is estradiol cypionate (ECP) used for? is a small or large dose required? when is it usually administered?
the most available for of estrogen used for termination of pregnancy
-larger dose needed for efficacy
-during estrus (bc dog breeds during estrus)
dog - 3 estrogen products used for contraception/pregnancy termination
-ECP
-estradiol benzoate
-oral DES
dog - true or false: oral diethylstilbestrol has a high efficacy for pregnancy termination/contraception
false: many doses not effective
-also not available in food animals bc we don't want it in the food chain
dog - true or false: prostaglandin use for is not approved in the bitch
true: it is only used for abortion bc it is not a physiological agent in pregnancy
dog - what does PGF2a cause? small dose or large? when does it not work? when does it work?
-luteolysis (thought not a NATURAL mechanism)
-large dose (bc the CL is quite refractory)
-does not work if given at 1-5 days of DE (no change in P4)
-works if given at days 5-8 and later in DE (causes P4 to decline)
dog - what does PGF2a cause physically?
contraction of uterine muscle
dog - side effects of PGF2a beginning w/i 5-15 minutes of administration, long range sideeffect
-vomiting, hyperpnea, hypersalivation
-shortened interestrus interval/luteal phase (dog comes into heat a lot sooner than would have expected)
dog - single or multiple doses of PGF2a are used?
multiple bc single dose needed is too close to the lethal dose
dog - dosage protocols for PGF2a
-give small doses every 8 hrs for 2 days, followed by doubled dose every 8 hrs until pregnancy terminated (no more discharge)
OR
-cloprostenol: give 3 doses, every 48 hrs
dog - what can you add to reduce the dosage needed of PGF2a?
other abortifactive agents
-cabergoline
-bromocriptine
-dexamethasone
dog - what do prolactin inhibitors help with?
abortion and pseudopregnancy (bc prolactin can induce pseudopregnancy)
dog - agents used for abortion in the dog
estrogen, PGF2a, prolactin inhibitors, dexamethasone, mifepristone, aglepreistone, epostane
dog - agents used for contraception/estrus control
androgens/testosterone, progesterone
dog - what is prolactin?
a luteotrophic agent
dog - if given after midgestation, what can prolactin inhibitors do?
interfere w/normal prolactin prod'n and release causing luteolysis, reduced P4, and pregnancy loss
dog - name 3 prolactin inhibitors
bromocriptine, cabergoline, metergoline (Contralac)
dog - side effects of bromocriptine
vomiting and anorexia (human drug)
dog - what is cabergoline, how is it given, what is it used for in europe, and when is it most effective?
-prolactin inhibitor
-given orally and injection
-pseudopregnancy
-when used as a sole drug, most effective in late pregnancy
dog - another name for metergoline
contralac
dog - what is Dexamethasone used for, how is it given? what are some side effects?
-used to terminate pregnancy
-given 2-3 times daily for 5-10 days, sometimes on tapering dose (usual for steroids)
-PU/PD
dog - what is mifepristone? what does it do? when is it given? how is it given?
-prolactin inhibitor (RU486)
-acts by binding competitively with P4 receptors, therefore terminating pregnancy
-after 32 days of pregnancy
-either bid orally for 4.5 days or single treatments with much higher doses
dog - what is aglepristone? what is it used for? when is it used? how is it given?
-anti-progesterone used to successfully initiate parturition
-used from 0-45 days after mating
-2 injections give 24 hrs apart
dog - what is epostane used for? MOA?
-used to terminate pregnancy or as a contraceptive
-acts by inhibiting 3B-hydroxysteroid dehydrogenase which catalyzes pregnenolone --> P4
dog - what is mifepristone? what does it do? when is it given? how is it given?
-prolactin inhibitor (RU486)
-acts by binding competitively with P4 receptors, therefore terminating pregnancy
-after 32 days of pregnancy
-either bid orally for 4.5 days or single treatments with much higher doses
dog - what is aglepristone? what is it used for? when is it used? how is it given?
-anti-progesterone used to successfully initiate parturition
-used from 0-45 days after mating
-2 injections give 24 hrs apart
dog - what is epostane used for? MOA?
-used to terminate pregnancy or as a contraceptive
-acts by inhibiting 3B-hydroxysteroid dehydrogenase which catalyzes pregnenolone --> P4