exam 1 pt. 1 (HPG axis, cyclity between species, and lactation)

hypothalamus-pituitary-gonads

HPG axis stands for what:

polyestrous

cycles that occur regularly throughout the year

seasonal polyestrous

cycles confined to a season of the year

monoestrous

1 cycle per year

17-21/28

a typical cycle for a polyestrous animal is what range of days?

1. cow

2. sow

2 examples of polyestrous animals:

1. mare

2. small ruminants

2 examples of seasonal polyestrous animals:

small animals

main example of monoestrous animal:

GnRH

hormone released by the hypothalamus:

stimulate the pituitary to release gonadotropes

action of GnRH:

1. LH

2. FSH

2 gonadotropes released by the pituitary:

induce ovulation

main job of LH:

stimulate a follicle

main job of FSH:

1. estrogen

2. inhibin

2 hormones released by the follicle:

estrogen; the LH surge

what specifically released by a dominant follicle tells the pituitary we need no more FSH? what does it then cause?

progesterone

once a corpus luteum is formed from a follicle, what hormone will it release?

corpus luteum

what is ALWAYS hard evidence that ovulation has happened and your patient is cycling?

1. follicular

2. luteal

2 phases of a females cycle:

1. follicle

2. estrogen

3. heat

with the follicular phase...

1. dominant ovarian structure?

2. dominant hormone?

3. animal is in ____

1. corpus luteum

2. progesterone

3. diestrus

with the luteal phase...

1. dominant ovarian structure?

2. dominant hormone?

3. animal is in ____

PGF2 alpha

hormone responsible to end CL destruction and bring animal into heat:

false

true/false: can estrogen and progesterone ever both be high

yes; when progesterone decreases

can follicular waves happen even with high progesterone? when will ovulation occur then?

follicles; will not ovulate however or show heat signs since progesterone is high

with follicular waves and high progesterone, what could we still feel on palpation and remember?

3-5mm/day

how big do follicles grow per day?

anterior

specific part the pituitary is releasing gonadotropes:

1. gonadorelin

2. deslorelin

2 drugs to mimic GnRH activity:

ending in "mate"

what drug name can indicate it is for a horse?

indirectly stimulate pituitary to release gonadotropes

how do our drugs mimic GnRH activity?

cause super ovulation

goal of mimicking FSH activity:

1. folltropin

2. eFSH

2 drugs to directly cause FSH activity:

hCG

main drug to directly cause LH activity:

cause ovulation

goal of mimicking LH activity:

1. CIDR

2. injectable

2 drugs to directly cause progesterone activity that ARE progesterone:

1. MGA

2. regu-mate

2 drugs to directly cause progesterone activity that are NOT progesterone:

they will not show up on bloodwork

with our 2 drugs that directly cause progesterone activity but aren't progesterone, what do we need to remember?

1. dinoprost

2. cloprostenol

2 drugs to directly cause PGF2 alpha activity:

cause smooth muscle contractions

side effect of administering drugs that mimic PGF2 alpha activity:

1. pregnancy support

2. synchronize/time AI

3. reduce estrus traits

3 reasons to give progesterone:

1. cow

2. doe

3. mare

4. sow

4 animals that have a 21 day estrous cycle:

1. ewe

2. queen

2 animals whose estrous cycle is 17 days:

15 hours

duration of estrus for a cow:

36 hours

duration of estrus for a doe:

30 hours

duration of estrus for a ewe:

6-24 hours

what is the range that estrus can last in a cow?

12-72 hours

what is the range that estrus can last in a doe?

18-48 hours

what is the range that estrus can last in a ewe?

sustained LH rise

even though mare's have a 21-day cycle, what makes them unique compared to other female animals?

50 hours

duration of estrus for a sow:

7 days

duration of estrus for a mare:

12-96 hours

what is the range that estrus can last in a sow?

2-12 days

what is the range that estrus can last in a mare?

it has progesterone rise BEFORE ovulation

what makes a dogs cycle different?

oocyte has to go under another meiotic division before capable of being bred; breed 2-3 days after ovulation

what does it mean that a dog ovulates a primary oocyte? what does this mean then?

can cause vaginal prolapse

what is a risk to estrogen creating edema production in dogs?

progesterone keeps cervix closed during luteal phase, so pathogens can incubate inside the uterus

why are dogs at risk for pyometras?

animal needs mating to produce an egg

an "induced" ovulation means what?

1. camelids

2. cats

2 examples of animals that need induced ovulation:

true

true/false: pyometra's can happen to cats that have never mated

a cat that is not spayed that shows heat behavior in the ABSENCE of a male/mating

what is a "spontaneous" ovulation in a cat?

40 days

if a cat is mated/induced to ovulate, but does NOT get pregnant, what is their length of diestrus?

60 days

if a cat is mated/induced to ovulate and does get pregnant, what is their length of diestrus?

12 days

length of estrous cycle for a camelid:

6 months

length of estrous cycle for a dog:

5 days

duration of estrus for a camelid:

1. queen

2. dog

2 animals whose duration of estrus is 9 days:

4-5 days

range of duration of estrus for a camelid:

2-19 days

range of duration of estrus for a queen:

4-21 days

range of duration of estrus for a dog:

mare

only species to not ovulate outside the ovary:

ovulation fossa

where do mares ovulate since they don't release outside?

oviductal papilla; gives us the ability to flush out embryos

what exists at the entrance of the oviduct in mares? why is this important?

hymen

name for the vestibule-vaginal junction:

fibrocartilaginous rings

what in the cervix of a cow gives it the ability to keep out pathogens?

near/after parturition

when does lactation occur?

estrogen

what should we NEVER test for via blood?

until stimulation is removed

how long does lactation normally last?

calf stimulates --> oxytocin is released --> mammary alveoli contract

describe how "let down" occurs:

NO

does oxytocin have anything to do with milk production?

smooth muscle

what does oxytocin specifically cause to contract?

camelid

animal to have 2 ducts per teat:

ruminants

animals to have 1 duct per teat:

1. mare

2. sow

2 animals to have 2-3 ducts per teat:

with intramammary infusion of antibiotic paste

with ruminants and horses, how do we treat mastitis?

small animal

animals to have 5-6 ducts per teat:

systemically

with small animals, how do we treat mastitis?

1. mastitis

2. galactostasis

3. agalactia

4. inappropriate lactation

4 things that go wrong with lactation:

it oozes out

how does milk come out of a small animals teats compared to a large animals?

horses

all animals will get mastitis during lactation besides who?

milk cultures

how do you diagnose mastitis?

gross and physical

in large animals, mastitis gives what signs?

systemic and sick

in small animals, mastitis gives what signs?

NSAIDs

what do we treat mastitis with in small animals?

if mastitis in small animals doesn't improve by ______, there is a bad issue

galactostasis

when the animal is producing too much milk and it is accumulating in the mammary gland

1. weaning

2. stillbirth

3. litter-bearing species with small litter

3 times galactostasis occurs:

if you release the pressure in the mammary gland, it will stimulate it to produce more milk again

why is blind neglect a doable treatment to galactostasis?

agalactia

partial or complete absence of milk flow

get baby through and cull

in large animals, what is the treatment for agalactia?

domperidone; fescue toxicosis

in mares, what is the treatment for agalactia? what commonly causes agalactia?