35 - termination of preg

Question 1

indications for termination of pregnancy?

Answer 1

to preserve the health/well being of the dam

population control

misalliance [unwanted mating]

feeder heifers [for meat, not breeding]

termination of non viable pregnancies

Question 2

what species can the “morning after” method be used to terminate pregnancy?

Answer 2

canine

Question 3

what is the morning after Tx?

what drug and dosage?

when MUST it be given

Answer 3

estradiol benzoate (compounded)

0.2 mg/kg IM

given AFTER ovulation

Question 4

what is the mechanism of action for estradiol benzoate?

Answer 4

induces embryo degeneration and delays passage from uterine tube into the uterus

Question 5

side effects of estradiol benzoate?

Answer 5

bone marrow suppression (for high doses)

induction of p4 receptors => pyometra concern

prolongation of estrus

Question 6

how effective is “morning after” estradiol benzoate if the bitch is treated after ovulation?

Answer 6

100% effective at preventing pregnancy

Question 7

logistically, at what stage of the bitch’s cycle should you order the morning after drug if a mis mating occurs, to allow time for it to be compounded by a pharmacy?

Answer 7

when she is in pro estrus

that way, you have time to order it before she ovulates, to give the drug just after she ovulates

Question 8

what hormones should be measured to determine if a bitch will / has ovulated?

Answer 8

p4

LH

Question 9

how does estradiol benzoate (morning after) inc risk of pyometra?

Answer 9

bitch is under influence of p4 -> you treat her with e2 after ovulation -> receptors are amplified for p4 in the endometrium => inc risk for cyctic endometrial hyperplasia => pyometra

Question 10

when can luteolysis be induced in the ewe?

Answer 10

UNTIL day 50 of pregnancy

Question 11

drugs and dosages used to induce luteolysis in ewe?

Answer 11

2.5 mg dinoprost

125-250 ug cloprostenol

Question 12

when can luteolysis be induced in the cow / heifer?

Answer 12

UNTIL day 150 of gestation

Question 13

what drugs and dosages are used to cause luteolysis in cow?

Answer 13

25 mg dinoprost

500 ug chlorpostenol

Question 14

according to the label, until what day of pregnancy is Lutalyse labeled effective?

Answer 14

until day 90

Question 15

when can luteolysis be induced in sow?

Answer 15

after day 15, continuing through entire gestation

Question 16

what drug and dose is used to induce luteolysis in sow?

Answer 16

10 mg dinoprost

Question 17

when can luteolysis be induced in the nanny?

why?

Answer 17

anytime

b/c the pregnancy is CL dependent the entire pregnancy

Question 18

what drug is NOT used in the hembra to induce luteolysis?

Answer 18

dinoprost

Question 19

when can luteolysis be induced in hembra?

Answer 19

all gestation

Question 20

what drug and dose is used for luteolysis in hembra?

Answer 20

250 ug of cloprostenol

Question 21

when can luteolysis be induced in the mare?

Answer 21

until day 35 of gestation (for 1* CL)

Question 22

what drugs and doses for luteolysis in mare?

Answer 22

5 mg dinoprost

125 ug cloprostenol

Question 23

how old must the CL be in ALL SPECIES to be receptive to luteolysis?

in the sow?

Answer 23

all - 5 days

sow - 15 days

Question 24

at what point is the bitch examined to determine if luteolysis should be induced to terminate her pregnancy?

Answer 24

4 weeks after mating

Question 25

what is BEST method to terminate pregnancy in bitch?

Answer 25

spay her

Question 26

why is surgical termination preferred in the bitch over medical termination?

Answer 26

b/c PGs have many side effects => bitch will be VERY ill

Question 27

when is the best time to induce luteolysis in a bitch? why?

Answer 27

over 30 days after LH surge prior to 30 days, the CL has autonomous function and is very refractory to PGs after 30 days, CL is easier to lyse

Question 28

how long might it take to lyse the CL of the bitch? why?

Answer 28

may take up to 14 days bitch CL is very refractory to PG

Question 29

why is the CL easier to lyse after 30 days?

Answer 29

at this time, CL is dependent on prolactin and LH so is more fragile

Question 30

why is termination of pregnancy in bitch not performed NOT immediately after the mis mating?

Answer 30

b/c 60% will not be pregnant wait 4 weeks to see if she is pregnant

Question 31

after 45 days in the bitch pregnancy, how must the pregnancy be terminated?

Answer 31

remove uterus and inject each puppy thru the uterine wall with euthanasia solution

Question 32

what are 2 protocols for use of dinoprost to cause luteolytsis in the bitch? which is used and why?

Answer 32

ONE: 0. 05 mg/kg BID for one day 0. 1 mg/kg BID for one day 0. 25 mg/kg BID until empty, so typically for 5 days or more TWO: 0.01 mg/kg QID OPTION 1 is used b/c low dose option is NOT effective

Question 33

in addition to dinoprost, what else may be used in the bitch? why is it not used?

Answer 33

0.005 mg/kg cloprostenol BID until empty - typically 7 days or more a dog died in one study - so if you use it and the bitch dies, the lawyers will use this against you

Question 34

when selecting between dinoprost and clorprostenol, which is the better option for the bitch? why?

Answer 34

dinoprost d/t its ecbolic effects

Question 35

what class of drugs can be combined with PG for luteolysis in the bitch?

Answer 35

dopaminergic drugs

Question 36

what drug used commonly in Europe for bitch abortion is NOT legal in the USA? why not?

Answer 36

RU-486 human abortion drug

Question 37

what is mechanism of RU-486?

Answer 37

competitive p4 receptor blocker removes the effect of p4 on the endometrium to induce fetal death

Question 38

how to induce luteolysis in the feline? | at what time in gestation?

Answer 38

0.1 mg/kg PG BIT for 5-7 days after day 40

Question 39

t/f once the feline placenta has begun producing p4, the PG is no longer effective at causing abortion

Answer 39

false is effective after placenta begins producing p4

Question 40

after day 100, what drugs are used to cause luteolysis in cow?

Answer 40

PgF and dexamethosone

Question 41

t/f prednisolone may be used instead of dexamathasone in the cow for luteolysis

Answer 41

false prednisolone may NOT be used

Question 42

why is dexamethosone used in cow to induce luteolysis after 100 days?

Answer 42

stimulates pre partal fetal distress b/c fetal adrenal gland is well developed enough to respond

Question 43

how is dexamethasone administered in the cow and what amount?

Answer 43

25 mg IM

Question 44

what is used to induce parturition in the ewe after day 50? drug, amount and route of administration

Answer 44

dexamethosone 10 mg (can use up to 15 mg) IM

Question 45

why is PgF NOT effective at causing luteolysis in the ewe after day 50?

Answer 45

she no longer has a CL at this point

Question 46

how long does the hembra rely on CL for maintenance of preg?

Answer 46

entire gestation 11 mos

Question 47

what is used to end hembra pregnancy?

Answer 47

dexamethasone

Question 48

t/f the hembra CL is refractory to luteolysis, like the dog clinical significance?

Answer 48

false it is VERY sensitive - to corticosteroids so it is easy to abort on accident clin sig: topical Tx for derm conditions and drops for ophthalmic conditions may induce abortion in the hembra

Question 49

why must multiple doses of PgF be given to the mare between days 35-80 to cause luteylysis?

Answer 49

b/c she has accessory CLs by this time so needs multiple doses to lyse them all

Question 50

after what day will the mare have delayed return to estrus? why?

Answer 50

after day 35 b/c endometrial cups have formed and they cannot be destroyed

Question 51

what must be done after day 80 in mare gestation to abort medically? how is this accomplished? side affects?

Answer 51

destroy fetal placental source of p4 multiple high doses of dexamethasone mare may develop laminitis -> avoid using this Tx

Question 52

prior to day 35, what how can preg be terminated in the mare?

Answer 52

crush the conceptus | give dose of PG

Question 53

after day 80, how is abortion achieved in the mare surgically?

Answer 53

manual abortion u/s guided needle puncture to kill conceptus / fetus dilate cervix and remove fetus (may be alive - so must kill it after)

Question 54

what is used to dilate cervix of mare for manual abortion?

Answer 54

PgE2 or PgE1 (misoprostol)