Pharmacotherapeutics of the Reproductive System, Pt. 2

Question 1

What would be the drug of choice for promoting follicle development?

a. FSH
b. LH
c. hCG
d. progesterone

Answer 1

A

Question 2

What kind of drug can you use to induce a mare with pre-ovulatory follicles to ovulate?

a. FSH
b. progesterone
c. oxytocin
d. GnRH analog

Answer 2

D

Question 3

What is the reproductive effect of PGF2α on mares?

a. induciton of ovulation
b. induce luteolysis on a mature corpus luteum
c. suppress estrus
d. prolong the life span of a mature corpus luteum

Answer 3

B

Question 4

What is superovulation? What 3 drugs can be used to induce this?

Answer 4

ovulation of multiple follicles so that embryos can be transferred to multiple recipients

1. FSH* - short half-life
2. eCG/PMSG - longer half-life
3. PG 600 - 400 IU of eCG + 200 IU hCG

Question 5

Why is FSH preferred over eCG/PMSG to induce superovulation?

Answer 5

eCG has a longer half-life, which can cause prolonged ovarian stimulation that can reduce embryo quality

Question 6

Why do we try to control the induction of ovulation? How do drugs that induce ovulation work?

Answer 6

control the time of ovulation for timed AI to ensure the sperm is ready by the time of ovulation

mimics the luteinizing hormone (LH) surge that triggers ovulation

Question 7

What are the 2 major options to induce ovulation?

Answer 7

1. GnRH analogs
2. hCG - has LH-like properties

Question 8

What are the 3 clinical appications of inducing/suppressing estrus or libido?

Answer 8

1. synchronization so that multiple animals are in estrus at once
2. “short-cycling” - induce luteolysis earlier to breed faster
3. suppression of estrous behavior

Question 9

What are the main 2 ways of inducing estrus/libido in polyestrous species, like cows and horses? Which drugs do this?

Answer 9

1. terminate the luteal phase to shorten diestrus - PGF2α
2. withdrawal of prodestagens, like controlled internal drug release devices that will remove the negative feedback loop upon removal

Question 10

What is the main drug used to induce estrus/libido in monoestrus species, like dogs? What else can be used?

Answer 10

DOPAMINE AGONISTS that decreases prolactin, like Cabegoline

• estrogen (diethylstilbestrol)
• gonadotropins (FSH. LH)
• GnRH analogs

Question 11

How can we suppress estrus/libido?

Answer 11

• prolong the luteal phase
• prolong anestrus in female dogs

Question 12

What are the 2 ways that we can prolong the luteal phase to suppress estrus/libido?

Answer 12

1. EXOGENOUSLY - prodesterone/progestin controlled internal drug release devices (only progesterone and altrenogest in mares)
2. ENDOGENOUSLY - oxytocin given during mid-diestrus to downregulate the oxytocin receptor in the endometrium and prevent the release of PGF2α

Question 13

What 2 types of drugs are preferred to prolong anestrus in female dogs?

Answer 13

1. ANDROGENS - Mibolerone (negative feedback)
2. PROGESTINS - megestrol acetate

Question 14

What drugs are preferred to induce parturition in sows, mares, cattle, and dogs?

Answer 14

SOW = PGF2α +/- oxytocin

MARE = oxytocin, dexamethasone, PGE for cervical dilation

CATTLE = dexamethasone/flumethasone, PGF2α (Dinoprost, cloprostenol)

DOG = progesterone antagonist Aglepristone (not common)

Question 15

Why would we typically want to induce parturition?

Answer 15

don’t typically want farm animals to give birth at night

Question 16

How do drugs induce abortion? When can PGF2α be used?

Answer 16

induce luteolysis and promote uterine contraction

only when the pregnancy is maintained by the progesterone secreted by the corpus luteum

Question 17

What are 4 drugs can be used to induce abortion in a mismated dog? What is important to note?

Answer 17

1. multiple doses of natural PGF2α (Dinoprost) or synthetic PGF2α (Cloprostenol)
2. dopamine agonist (Cabergoline) to decrease prolactin
3. progesterone antagonist (Aglepristone)
4. estrogens (not recommended)

higher doses of prostaglandins are associated with substantial side effects including vomiting, diarrhea, and lethargy

Question 18

When does fetal mummification occur? How is it treated?

Answer 18

fetal death in utero and luteolysis does not occur, reuslting in a retained fetus that is not contaminated by bacteria while the cervix remains closed —> aseptic partial desiccation and absorption of fetal and placental fluids

PGF2α

Question 19

How can cryptorchidism and ovarian remnant syndrome be diagnosed? What 3 other diagnostic tests exist?

Answer 19

GnRH or hCG response test - if testosterone and estrogen increase as a response, tissue is present

1. Anti-Mullerian hormone assay
2. Witness LH test
3. Progesterone test after induction of ovulation

Question 20

What do clinically ill patients with pyometra typically benefit from? How can it be medically treated?

Answer 20

IV fluid therapy and parenteral antibiotics

PGF2α, Cabergoline, Aglepristone

Question 21

What is mammary fibroadenomatous hyperplasia in cats associated with? How is it medically treated?

Answer 21

prolonged progesterone

Cabergoline, Aglepristone, PGF2α

Question 22

What is benign prostatic hypertrophy? What are 4 possible treatments?

Answer 22

canine disease occuring in more than 80% of intact males over 5 years associated with the androgenic activity of duhydrotestosterone that is metabolized locally from testosterone by 5α-reductase

1. castration
2. 5α-reductase inhibitor: Finasteride
3. androgen receptor antagonistL Osaterone acetate, Flutamide
4. GnRH analog (deslorelin), progestins, and estrogens to inhibit the HPG axis

Question 23

What is overt pseudopregnancy?

Answer 23

canine condition resulting in nesting behavior and mammary gland development caused by decreased progesterone levels that causes increased prolactin

Question 24

Usually overt pseudopregnancy does not require treatment and will subside in 2-3 weeks. What can be used to stop it?

Answer 24

dopamine agonist (Cabergoline) —> decrease prolatin