Read Dog reproductive anatomy and physiology.ppt text version

Reproduction in the Dog

Reproductive Tract Anatomy of the Bitch

Ovary Uterine Horn Uterine Body Cervix Urethral Opening Constrictor Vestibuli Vulva Oviduct

Vagina Clitoris Fossa Clitoridis

Reproductive Tract Anatomy of the Bitch

Ovary Uterine Horn Oviduct

Mesometrium

Uterine Body Cervix

Vagina Vulva

Ovary

Completely enclosed with a fat covered peritoneal lining that is called the ovarian bursa. Ovary

Opening of Ovarian Bursa Uterine Horn

Mesovarium Ovarian Bursa

Uterus During Estrus

Cervix and Vagina

Cervix

Vagina

Vagina, Vestibule and Vulva

Vagina Constrictor Vestibuli Urethral Opening Clitoris Vulva

estibule

Fossa Clitoridis

Reproductive Tract Anatomy of the Male

Urethralis Muscle Penis

Rectum

Prostate Bladder Vas Deferens

pididymis Scrotum Testis Bulbus Glandis

Os Penis

Glans Penis

Reproductive Tract Anatomy of the Male

Bladder

Urethralis Prostate Muscle ulbocavernosus Muscle Crura Penis

Vas Deferens

Glans Penis Bulbus Glandis

Scrotum

Scrotum, Testis and Epididymis

External Cremaster Muscle Caput Epididymis Testis Scrotum Spermatic Cord

Pampiniform Plexus Corpus Epididymis

Stratum Subdarticu

Tunica Vaginalis Parietal

Testis, Epididymis & Spermatic Cord

Vas Deferens

Pampiniform Plex Caput Epididymis Testis Corpus Epididymis

Cauda Epididymis

Testis Anatomy

Vas Deferens

Corpus Epididymis

Testis Cauda Epididymis

Bulbus Glandis

Penis

Bulbus Glandis

Glans Peni

· Vascular shunting allows swelling of penis for erection. · Glans penis swells (Bulbus glandis) for locking penis in the vagina of female.

Os Penis and Bulbus Glandis

Os Penis Penis

Vascular area of Bulbus Glandis

Os Penis

Bone

Os Penis

Groove

Canine Physiology and Reproduction: Male

I. Ejaculation a) Occurs within 80 seconds (sperm rich fraction). II. Semen Characteristics a) Three fractions 1) Clear fluid (Urethral Gland): 0.1 - 3.0 ml 2) Milky fluid (Sperm Rich): 0.5 - 4.0 ml 3) Clear fluid (Prostate Gland): 1 - 30 ml

Canine Physiology and Reproduction: Bitch

I. Physiology a) Puberty 1) 6 to 7 months (range 4 to 22) 2) Breed dependent ® Smaller breeds earlier than larger b) Oestrous cycle 1) Type: mono-estrus ® ® Indication of seasonal: Feb to May Cycle randomly throughout year

2) Length between cycles

Canine Physiology and Reproduction: Bitch

2) Length between cycles ® Mean: 7 months (range 4­13) 3) Stages ® Proestrus: 9 days (range 2­27) · Physical turgid swelling of vulva and appearance of a bloody discharge · Vaginal cytology will change with very early non-cornified epithelial cells increasing towards end of proestrus.

Canine Physiology and Reproduction: Bitch

· Behavior - bitch is restless and secrete pheromones but is aggressively negative towards male becoming more passive towards start of estrus ® Oestrus: 9 days (range 3­21) · Bitch accepts male

· Vulva swelling will soften and discharg will be slightly pink to straw-colored. · Vaginal cytology will have a high concentration of cornified epithelial cells with little debris.

Canine Physiology and Reproduction: Bitch

· Discharge is straw colored rather than blood stained ® Metoestrus: 90 days · Non-acceptance of males · Loss of vulva swelling and no discharge. Vaginal cytology is no cornified cells and high numbers of White Blood Cells. ® Anoestrus: 75 days · Period of ovarian inactivity and no vaginal discharge · Breed dependent

Canine Physiology and Reproduction: Bitch

® Pseudo-pregnancy: · Extension of metestrus period in which progesterone concentrations remain elevated. · Female will have nest building behavior and enlarged mammary glands

Behavioral Changes During Estrus in the Bitch

Vulva Swollen and Enlarged Bloody discharge from vulva Aggressive towards Male

Copulation

Passive

Provides sexual posturing to male for copulation

Proestrus

Estrus

-8

-4

0

+4

+8

+12

Indicates Day of Peak in LH

Canine Physiology and Reproduction: Bitch

c) Ovulation 1) Associated with LH peak ® Ovulation: 48 hours post LH peak ® Oocyte maturation · 4-5 days post LH peak · 2-3 days after post ovulation ® Peak fertility · 0-5 days 2) Detection of ovulation ® Vaginal cytology · Only accurate for detecting oestrus

Vaginal Cytology in the Bitch

Cell Type Para basal Small Large Anuclear Red Neutrophils Intermediate Intermediate Keratinised Blood

Proestrus Early Late Estrus Early Late Metestrus Early Anestrus

+++ + ++

+++ ++ + +

+/++ +++ +++ -

++ ++++ +++ +/-

+ +++ ++ +/-

+ + +++ +

Vaginal Cytology - Early Proestrus

Small Intermediate Cells

Parabasal Cell

Vaginal Cytology - Proestrus

Red Blood Cells

Vaginal Cytology - Proestrus

ed Blood Cell

Parabasal Cell

Large Intermediate Cel

Vaginal Cytology - Early Estrus

Vaginal Cytology - Estrus

Anuclear Keratinised

Large Intermediate

Vaginal Cytology - Diestrus

Neutrphils Neutrphils

Small Intermediate-Parabasal

Vaginal Cytology - Anestrus

Canine Physiology and Reproduction: Bitch

2) Detection of ovulation (cont)

® Progesterone concentrations

· Progesterone concentrations rise prior to ovulation · Progesterone concentrations can be measured to determine day of ovulation and breeding, but concentrations are highly variable · Baseline Progesterone = 1 ng/ml · Day Preceding Ovulation = 3-4 ng/ml · Day of Ovulation = 4-8 ng/ml

· Follicles start to luteinizebefore ovulation

Hormonal Patterns During Estrous Cycle of Bitch

Fertile Period Arbitrary Plasma Concentrations Ovulation Estrogen

Completion of Meiosis I Fertilization

Progesterone LH

-10 -6 -4 -2

Days from LH Peak

0

2

4

8

12

14

Hormone Concentrations During Pregnancy and Parturition

Parturition Mating Arbitrary Plasma Concentrations Prolactin Progesterone

Corticosteroid

Total Estrogens

0

10

20

30

40

50

60

70

Days of Pregnancy

Canine Physiology and Reproduction: Bitch

d) Mating ­ only when Bitch is in standing heat 1) Dog achieves intromisssion by vigorous thrusting of hind quarters 2) Bulbus glandis swells (6x4 cm) in vagina 3) Male dismounts, but remains connected and facing away from Bitch, penis bent at a 180° angle 4) Vulva sphincter muscles contract around penis forming " copulatory tie" ® Ejaculation of seminal fluid (2-30 mL) ® 20 minute average (range 5­60) ® Not essential for conception

Mating in dogs

First Stage of Coitus

The "Turn"

Second Stage of Coitus The "Tie"

Semen Collection of Male Extension into AV

Ejaculation

The Turn

Canine Physiology and Reproduction: Bitch

e) Pregnancy 1) Duration: 63 days (range 58 ­ 68) 2) Diagnosis ® Abdominal Palpation: day 21-28 ® Radiography: day 45 ® Ultrasonography: day 24-28 f) Parturition 1) Signal for initiation ® Maturation of fetal pituitary-adrenal axis via cortisol secretion

Canine Physiology and Reproduction: Bitch

2) Impending signs of parturition ® Behavior: nest building, restlessness and seeking quiet, out of sight areas ® Vulva becomes swollen, edematous and may have some vaginal discharge ® Relaxation of pelvic and abdominal muscles ® Presence of milk in mammary gland is not an accurate sign ® Decrease in body temperature from 38 to 37oC just before parturition.

Canine Physiology and Reproduction: Bitch

3) Stages of parturition ® First: mean 4 hours, last up to 36 · Period in which the cervix dilates · Bitch will be uneasy, refuse food, pant, vomiting and frequently looking at flank. ® Second:length variable · Visible straining of bitch in the sitting position · Placental membrane will break and fluid discharged from vulva

Canine Physiology and Reproduction: Bitch

® Second: cont · Amnion covering the pup will be visible as it passes through the cervix, vagina and out the vulva · Membrane will rupture spontaneously or by licking of dam · Start of labor (active contractions) first fetus cannot be expected to survive more than 6 hours in the uterus · Fetuses delivered within 2 hours of each other

Canine Physiology and Reproduction: Bitch

® Second: cont · Usually interval between puppies is about 30 minutes ® Third: · Foetal membranes expelled 5-15 minutes 4) Dystocia- difficult birth ® Symptoms

· Abnormal fetal presentation, position o posture

Canine Physiology and Reproduction: Bitch

4) Dystocia- difficult birth ® Symptoms (cont) · Strong and persistent labor for 20 minutes without delivery of fetus · Weak and infrequent contractions for 2 to 3 hours · > 4 hours from delivery of last fetus (if not last one) ® Causes · Most common is uterine inertia (weak contractions), size of fetus and birth canal

Preparation for Parturition in the bitch Bitch should be placed in a whelping box at least one week prior to parturition. Whelping box should be raised above the floor and large enough for the bitch to move freely. Bottom of box should be covered with newspapers for easy cleaning. It is necessary to have rail along the inside of the box to prevent puppies from being laid on.

Whelping Box Clean bedding and light source for heat

Picture courtesy Dr. Joseph McCann, RockErin Kennels

Side Rail protect pups from being laid on by bitch

Picture courtesy Dr. Joseph McCann, RockErin Kennels

Whelping Box

Easy access by bitch to nurse

Picture courtesy Dr. Joseph McCann, RockErin Kennels

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Dog reproductive anatomy and physiology.ppt

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