Mismating Management, Contraception, Ovarian Remnant Syndrome

Question 1

Mismating initial consult

Answer 1

• is she in heat
• was a tie observed
• how long was bitch missing
• are puppies wanted
• is the bitch a breeding animal
• will you let me spay her (pyometra/neoplasia)

Question 2

Perform ______ on all mismatched bitches

Answer 2

Vaginal cytology

• want to determine where she is at in her cycle
• look for sperm heads (24 hrs after breeding, 75% in 48 hrs)
• run P4 to confirm if needed

Question 3

Goals of mismating

Answer 3

• limit treatment to dogs at highest risk or those confirmed pregnant
• do not want to affect future fertility
• do no harm

Question 4

First opportunity to confirm pregnancy in a dog

Answer 4

22-24 days

- do an ultrasound

Question 5

Options for pregnancy termination

Answer 5

• ovariohysterectomy
• prostaglandin
• estrogen
• prolactin inhibitors
• corticosteroids
• progesterone anatgonists

Question 6

Examples of prostaglandins

Answer 6

Lutalyse and Estrumate

Question 7

Prostaglandins - mode of action

Answer 7

Direct luteolytic action with multiple doses (canine CL are resistant early in pregnancy)

• removes source of progesterone
• causes myometrial contractions
• dilates cervix
• pregnancy is expelled

Question 8

Prostaglandins - side effects

Answer 8

Therapeutic dose is relatively high compared to large animals, and they are sensitive to it

• panting
• excessive salivation
• vomiting
• diarrhea
• begins within 5 min and lasts 20-30 min
• subside with repeated use
• bitch may return to estrus sooner

Question 9

How to minimize side effects of prostaglandin

Answer 9

• give on empty stomach
• start with lower doses and increase
• dilute with saline
• walk immediately after injections
• atropine
• pregnant women and people with asthma handling prostaglandins should take extreme care!

Question 10

Estrogens

Answer 10

Can be used only during estrus!

• good client communication and consent is important
• do not use in valuable breeding bitch

Question 11

______ is the only product that can be used at the time of mating to prevent pregnancy!

Answer 11

Estrogen

Question 12

Estrogen - mode of action

Answer 12

Tightens utero-tubular junction

• kink formed in oviducts
• delays tubular transport of embryos
• alters estrogen:progesterone ratio leading to implantation failure
• direct embryotoxic effect
• collectively leads to failure of pregnancy maintenance

Question 13

Estrogen - side effects

Answer 13

• pyometra (if treated during diestrus)
• bone marrow suppression
• prolonged estrus
• infertility at subsequent cycles

Question 14

Estrogen products

Answer 14

• estradiol cypionate
• estradiol benzoate
• diethylsilbesterol (DES) is NOT effective mismating agent

Question 15

Corticosteroids - mode of action

Answer 15

High cortisol levels cause fetal production of prostaglandins leading to abortion

• may have direct luteolytic actions
• exact mechanism not fully understood

Question 16

Corticosteroids - side effects

Answer 16

• anorexia
• PU/PD
• short duration
• subside after medication is discontinued

Question 17

Corticosteroid - products

Answer 17

Dexamethasone

• always start after day 30 of gestation
• always confirm pregnancy loss

Question 18

Prolactin inhibitor - products

Answer 18

• parlodel

- dostinex

Question 19

PRL - mode of actions

Answer 19

Increases dopamine release

• dopamine inhibits prolactin release
• prolactin is primary luteotropin in bitch
• low prolactin levels lead to low progesterone levels
• low progesterone = abortion/pregnancy loss

Question 20

PRL inhibitors - side effects

Answer 20

• nausea, vomiting
• anorexia
• diarrhea
• seen commonly with bromocriptine
• rare with cabergoline (more selective dopamine agonist)

Question 21

PRL inhibitors always start _____

Answer 21

After day 30 of gestation

- confirm pregnancy loss at end of treatment

Question 22

Progesterone antagonists

Answer 22

• mifepristone (not available in US)

- aglepristone: requres 2 shots, 24 hrs apart as early as 3rd week of gestation

Question 23

Notes to remember

Answer 23

• failures occur when follow up is neglected
• progesterone levels of <1 at completion assure luteolysis
• make owners aware of expectations
• don’t make abortifacient use the cheap alternative to spay

Question 24

Intratesticular injection of sclerosing agents

Answer 24

Neutersol/Esterilsol

• scleroses the testicle to damage ability to produce sperm (does not eliminate it totally)
• low chance of achieving pregnancy
• some effect on testosterone

Question 25

GnRH vaccines

Answer 25

Gonacon

Question 26

GnRH agonists

Answer 26

Gonazon, suprelorin

- reversible, down regulates hypothalamic pituitary gonadal axis

Question 27

GnRH antagonists

Answer 27

Acyline

Question 28

Neutersol/Zeuterin/Esterilsol

Answer 28

Zinc gluconate

• intratesticular injection
• results in sterility due to destruction of sperm production
• some effect on testosterone production

Question 29

Ovariectomy

Answer 29

Uterus is left, but ovaries are removed

• fewer complications reported with ovariectomy
• common in European countries

Question 30

Ovary sparing spay

Answer 30

Ovaries remain

• must remove cervix or pyometra
• lots of owner counseling/understanding

Question 31

Vasectomy

Answer 31

Only renders male sterile, but still will have testosterone present
- castrate and prosthesis is alternative

Question 32

Flank spay in cats

Answer 32

Used in cases of mammary hyperplasia

Question 33

Hormone profile of ORS females

Answer 33

• elevated anti-mullerian hormone level
• confirm rising P4 2 weeks later (P4>2 confirms presence of luteal tissue)
• high estrogen
• LH concentration is low on 2 separate tests

Question 34

ORS - things to consider

Answer 34

• LH rises slowly and variable in spayed female
• high P4 and E2 confirmatory, but low values are not predictive enough
• unstimulated P4 testing doesn’t work in cats

Question 35

Side effects of ORS medical management

Answer 35

Megestrol acetate (ovaban) or mibolerone (cheque)

• mammary gland tumors
• acromegaly
• clitoral enlargement
• adrenocortical suppression