Control over Canine Reproduction

Question 1

What are the indications for terminating pregnancy?

Answer 1

Bitch not intended for breeding.
Incorrect dog serves bitch
Obstetric risk

Question 2

How does PGF2 alpha cause abortion?

Answer 2

Causes luteolysis and uterine contractions in second half of gestation.

Question 3

Owner has requested to terminate pregnancy in her bulldog. The dog is in it’s 2nd half of gestation and money is not an issue what do you do?

Answer 3

Progesterone receptor antagonists.

Eg. Alizine or Aglipristone two doses 24 hours apart.

Question 4

What are the two names for prostaglandin f2 alpha products used?

Answer 4

Closprostenol

Lutalyse

Question 5

What are an issue with using PGF2 alpha use to cause abortion?

Answer 5

Nausea, vomiting, diarrhoea, abdominal pain

Question 6

How does progesterone receptor antagonists cause abortion?

Answer 6

Acts on progesterone receptors.
No progesterone = no pregnancy.
Very expensive and can be irritant.

Question 7

What must you always ensure when inducing pregnancy termination?

Answer 7

Check all foetuses have aborted before stopping treatment.

Question 8

How do dopamine agonists/prolactin inhibitors cause abortion?

Answer 8

No prolactin - corpus luteum is not supported and pregnancy is at risk

Question 9

How can oestrogen be used to terminate pregnancy?

Answer 9

Prevents implantation when given within a few days of mating

Question 10

What is the purpose of glucocorticoids to cause abortion in the bitch?

Answer 10

Difficult - need a high dose for a long period.

Question 11

What are you going to do if the owner suspects unwanted insemination?

Answer 11

Spay.
Treat with aglipristone for a week after mating.
Can do vaginal cytology to check for oestrous/sperm.

Question 12

List methods of preventing/suppressing oestrous in companion animals.

Answer 12

Ovariectomy.
Progestagens.
Androgens.
GnRH agonists.

Question 13

What are some effects of neutering?

Answer 13

Obesity, prostate neoplasia, reduced sexual behaviour, reduced mammary neoplasia, reduced pyometra, no effect on bone density.

Question 14

Give examples of progestagens and explain the side effects and how they work.

Answer 14

Megestrol acetate (Ovarid) or Medroxyprogesterone acetate (Provera).
Unknown mechanism of action. 
Side effects - CEH, pyometra, benign mammary nodules, mammary neoplasia, increased appetite, behaviour changes, skin changes.

Question 15

What is Mibolerone?

Answer 15

Androgen. Used to prevent gonadotrophin release and ovulation.
Issues with clitoral enlargement, vaginitis, mascularisation.

Question 16

Why does progestagen cause pyometra?

Answer 16

Oestrogen potentiates the effects of progesterone on uterus.

Question 17

What is the use of deslorelin acetate in canine reproduction?

Answer 17

GnRH agonists.
Get reversible sterility in male dogs not for use in bitches.
If you don’t remove the implant you get continued GnRH presence.

Question 18

What are some indications for inducing oestrous?

Answer 18

Delayed puberty
Anoestrous
Synchronising ovulation for embryo transfer
Suit breeder schedule

Question 19

What are the pre-requisites for inducing oestrous?

Answer 19

Healthy bitch. 4 months since last oestrous. Exclude any illness, metabolic issues, intersex etc.

Question 20

Compare Cabergoline and Deslorelin implant.

Answer 20

Cabergoline - induces fertile oestrous, pro-oestrous in 3-8 days.
Deslorelin - pro-oestrous within few days, remove implant to avoid abortion.

Question 21

How do you suppress oestrous in the cat?

Answer 21

Induce ovulation/luteal phase using hCG, GnRH or cotton bud in vagina

Question 22

How do you want to control reproduction in males?

Answer 22

Castration.
Vasectomy.
GnRH agonist (Deslorelin)
Intra-testicular injections of zinc gluconate

Question 23

How do you treat benign prostatic hypertrophy?

Answer 23

5 alpha reductase inhibitors - inhibits conversion to testosterone.
Progestagens - not enough contraceptive effect