Small Animal 1

Question 1

describe canine estrous cycle basics

Answer 1

monstrous, non-seasonal, 2 estrus periods each year, and dormitory effect (co housing anestrus dogs with pro/estrus ones will make anestrus shorter)

Question 2

give lengths of each stage of dog estrous cycle

Answer 2

anestrus 4 mo, proestrus 9 days (0-27), estrus 9 days (4-21), diestrus 2 mo

Question 3

during deep anestrus in dog, ___ and ___ are low, the towards end of this phase they increase, as well as follicular development occurs causing ___ rise

Answer 3

FSH and LH; E2

Question 4

during proestrus __ grow which cause ___ to rise and then peak at end of phase

Answer 4

estrogen

Question 5

what hormone is low during proestrus until late proestrus

Answer 5

progesterone

Question 6

o Serosanguinous discharge (diapedesis)
o Vaginal mucosa appears smooth (edema)
o Vulva swells (firm to touch; edema)
vaginoscopy: mucosa glistens and rounded edges
–> these changes occur during what phase of estrous?

Answer 6

proestrus

Question 7

during estrus, ___ which peaked in proestrus is now declining, ___ increases due to follicles, ___ surge occurs causing ovulation

Answer 7

E2, P4, LH

Question 8

straw-colored vaginal discharge, softened vulva, and vaginalk mucosa wrinkles (decreasing edema)
during what phase?
and due to decline of what hormone?

Answer 8

estrus! decline of estrogen (remember it peaked at end of proestrus)

Question 9

dogs ovulate a primary or secondary oocyte?
MOST species ovulate a primary or secondary oocyte?

Answer 9

primary doggy, secondary others
(significance: after ovulation is complete (which is about 25 h) then takes 2 days for primary oocyte to mature and become a secondary oocyte that can be fertilized)

Question 10

during diestrus, female is not receptive to mating, __ is low, and ___ increases rapidly, peaking 3-4 weeks after onset of diestrus

Answer 10

E2 low, P4 increase

Question 11

what phase

Answer 11

diestrus

Question 12

label hormones

Answer 12

Question 13

what cell type is this

Answer 13

anuclear cell

Question 14

what cell type is this

Answer 14

superficial cell (pyknotic (dense) nucleus, angulated shape, nucleus not stippled)

Question 15

what cell type

Answer 15

intermediate cell (stippled nuc, large cytoplasm)

Question 16

what cell type

Answer 16

paranasal cell, large nuc to city ratio and very round

Question 17

which is early and which is late proestrus? vaginal cytology

Answer 17

Question 18

what phase is this? early or late?

Answer 18

early proestrus: we are seeing parabasal cells, intermediate cells, WBCs, PMN type (will not always be present), RBCs (will not always be present)

Question 19

what phase is this? early or late?

Answer 19

late proestrus: we are seeing superficial cells rather than paranasal and intermediate cells because it is late phase. also some WBCs (PMN) (not always present); sometimes RBC will be present too

Question 20

what phase

Answer 20

estrus. most cells are cornified (late proestrus, most cells cornfield too, BUT with estrus there are NO PMNs and NO RBCs so the background looks clean)

Question 21

what phase

Answer 21

diestrus. there are intermediate cells, paranasal cells, WBCs, and (on day 1) an abrupt decline in cornified cells occurs

Question 22

order these events in dog: ovulation, oocyte maturation, LH peak, start of estrus

Answer 22

estrogen peaks during proestrus –> triggers LH peak marking 1-2 days into estrus (elsewhere says LH peak = estrus start, so a bit confused there) –> ovulation 1-2 days after LH peak –> ovulation can take 24 h –> oocyte matures

Question 23

canine specific feature: ____ rises during estrus, so can be used go time ovulation

Answer 23

progesterone

Question 24

give levels of progesterone in canine: before LH peak, day of LH peak, when ovulation occurs, and when oocyte matures

Answer 24

<1, 2, 4-6, and 15 ng/mL (progesterone is rising during estrus)

Question 25

3 ways of breeding management in a dog (what semen types)

Answer 25

female and stud same location, fresh semen, or frozen semen

Question 26

for breeding management in dog, you want to perform what every other day and then start __ testing when 60-70% cornified

Answer 26

vaginal cytology; P4

Question 27

how long is sperm viable? different for different storage methods of sperm?

Answer 27

fresh semen, sperm viable 48 h to 11 days, chilled at lest 48 h, frozen only 12 h

Question 28

one ____ measurement has NO use in canine breeding and should always be used with other clinical assessments, eg. behaviour, vaginal cytology, vaginoscopy, and LH test

Answer 28

progesterone

Question 29

best method for suppressing estrus in female not intended for breeding

Answer 29

OVH

Question 30

a female intended for reproduction needs how long for uterus to involute and repair, after a cycle?

Answer 30

130 to 150 days
if <120, infertility possible

Question 31

name 3 hormone types used for estrus suppression. what is best option?

Answer 31

Progestogen – No universally safe/effective protocol
* Androgens – Not recommended for longer than 24 mo
* GnRH agonists – Good response, potentially best option

Question 32

what progestin used for estrus suppression CANNOT be used to treat more than 2 cycles in a row and can’t be used to treat at pubertal estrus*

Answer 32

megestrol acetate
additional info: contraindicated in pregnant dogs and females with DM; uterine disease in <1% of females

Question 33

what progestin used for estrus suppression is a long-acting progestin, used only in anestrus, and has COMMON SIDE EFFECTS? what are the 2 side effects?*

Answer 33

MPA, medroxyprogesterone acetate
uterine disease in 4-10% of females and increases incidence of mammary gland tumours

Question 34

if you suspect a false pregnancy, what must you make sure to check before treating?

Answer 34

ensure patient is NOT pregant! otherwise you will induce abortion

Question 35

what are the 3 anti-prolactin drugs used for false pregnancy?

Answer 35

bromocriptine, a dopamine agonist
cabergoline and metergoline, serotonin antagonists

Question 36

how do anti-prolactin drugs treat false pregnancy?

Answer 36

Pseudopregnancy happens when the progesterone levels begin to fall as decreasing progesterone leads to an increase of the hormone prolactin. Prolactin is responsible for the behaviours seen during pseudopregnancy.

dopamine inhibits prolactin secretion, so can use dopamine agonist (bromocriptine)
serotonin stimulates prolactin secretion, so can use serotonin antagonist (cabergoline, metergoline)

Question 37

what progestin drug can be used for false pregnancy

Answer 37

megestrol acetate

Question 38

is false pregnancy related to pyometra?

Answer 38

no

Question 39

false pregnancy (pseudopregnancy, pseudocyesis, galactorrhea) happens when ______ levels begin to fall, causing an increase in ______, the hormone responsible for behaviours seen in pseudopregnancy

Answer 39

progesterone, prolactin.

Question 40

when does false pregnancy occur in female dogs

Answer 40

2-3 mo after estrus, 3-4 days after OHE, or 3-4 days after discontinuation of exogenous P4

Question 41

is false pregnancy common? what 2 signs might you see?

Answer 41

common, 65% on regular basis

in 2 mo diestrus, can see mammary gland development and then at end of diestrus increase in milk production

Question 42

what estrus suppression progestin drug can be used at any phase of cycle and has a low incidence of uterine disease (<0.3%)?

Answer 42

proligestone! unfortunately not in Nam yet

Question 43

what estrus suppression androgen drug must be given 30 days before proestrus starts and then estrus returns after 70 days of cessation?

Answer 43

mibolerone

Question 44

you give a GnRH AGONIST for estrus suppression. what is the initial effect? what happens with sustained exposure?

Answer 44

initially: mimics GnRH, so get LH and FSH stimulation (flare up effect, ie. a short estrus)
then with sustained exposure, there is reduced GnRH-stimulated gonadotropin secretion due to GnRH receptor DOWNREGULATION and decreased receptor expression

Question 45

how are GnRH AGONISTS for estrus suppression delivered?

Answer 45

SQ impact–remember these are long acting (last 6-12 mo)

Question 46

how do GnRH ANTAGONISTS work?

Answer 46

pituitary block of GnRH receptors, so immediately suppress gonadotropins. (however, need very high doses, repeated treatments, and no commercial product, so very limited use)