Small Animal Reproduction- Lecture 20

Question 1

Monoestrus

Answer 1

One estrous cycle per year.

Domestic dogs, non-seasonal.

Question 2

Bitch

Answer 2

Intact female

Question 3

Dog

Answer 3

Intact, stud, dog

Question 4

Puberty

Answer 4

Onset of first estrous cycle.
6 months to 2 years of age.
Small vs. Large bitches.

Question 5

Interestrus interval

Answer 5

Time between one proestrus and the next (4.5- 12 months).
German shepherd is shorter time.
Basenji has longer time, a whole year.

Question 6

Stages of estrous

Answer 6

Proestrus, estrus, metestrus, diestus.

Question 7

Follicular phase

Answer 7

Subdivided into proestrus and estus.

Question 8

Luteal phase

Answer 8

Dominated by progesterone. In the bitch, not generally subdivided.

Question 9

Canine estrous cycle

Answer 9

Proestrus, estrus, diestrus, anestrus.

Question 10

Vaginal cytology

Answer 10

Can get a basic idea of where a bitch is in estrous cycle.
Cornified epithelia cells shows the progression of epithelia cell death resulting from tissue thickening due to estrogen.

Question 11

Parabasal cells

Answer 11

sunny side up.

Seen during proestrus

Question 12

Intermediate cells

Answer 12

over easy.

Seen between proestrus and estrus. also diestrus and anestrus.

Question 13

Superficial cells

Answer 13

pyknotic nucleus.

Seen during estrus.

Question 14

Estrogen

Answer 14

Vaginal lining epithelial cells and wall thickness.

Behavior and physical signs.

Question 15

Progesterone

Answer 15

Produces in pregnant and non-pregnant bitches.

Question 16

Relaxin

Answer 16

Produced by canine placenta. Relaxes pelvic canal and cervix.
Blood test for pregnancy determination.

Question 17

Proestrus

Answer 17

Length: 0-27 days.
Behavior: non-receptive to male.
Cytology: progressive cornification.
Anatomy: vulvar swellings and serosanguinous discharge.

Question 18

Estrus

Answer 18

Length: 4-24 days.
Behavior: receptive.
Cytology: prominent cornification.
Estrogen falling. Progesterone rising. LH peak (short- less than 24 hrs), ovulation occurs 24 to 48 hrs later.

Question 19

Ovulation is different for the bitch

Answer 19

They ovulate primary oocytes!
Then they mature with meiosis to secondary oocyte prior to fertilization- takes 24 to 48 hrs.
Breed 4 to 6 days after LH peak for optimal results.

Question 20

Diestrus

Answer 20

Behavior: not receptive.
Cytology: abrupt change to non-cornification.
High progesterone.
Anatomy: less vulvar swelling.

Question 21

Anestrus

Answer 21

Length: 4.5-5 months.
Behavior: non receptive.
Cytology: not cornified.
No progesterone or estrogen.
No vulvar swelling or discharge.

Question 22

Pregnancy

Answer 22

Progesterone high in diestrus, irrespective of pregnancy status- cannot use as pregnancy test.
CL dependent to term.

Question 23

Placenta type

Answer 23

Endotheliochorial.
Zonary.
Deciduate.

Question 24

Stage 1 parturition

Answer 24

Preparation.
Variable timing.
Nesting and poor appetite.
Cervical softening.

Question 25

Stage 2 parturition

Answer 25

``` Fetal expulsion. Contractions. Duration variable. Generally .5 to 1 hour between pups. Licks neonate. ```

Question 26

Stage 3 parturition

Answer 26

Fetal membrane passage- generally with each pup. | Bitch may eat membranes.

Question 27

Puerperium

Answer 27

Involution- prolonged minimum 2 months. | Lochia- variable (often brick red brown), several weeks, odorless.

Question 28

Pseudocyesis

Answer 28

``` Pseudopregnancy. Normal- every non pregnant diestrus. Progesterone fall stimulates prolactin rise. Prolactin instrumental in lactation. Overt vs. Covert. Latrogenic- OHE during diestrus. ```