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Presentation on theme: "Canine Reproduction ABDUL SAMIK DEPARTEMENT OF VETERINARY REPRODUCTION"— Presentation transcript:


2 Endocrine Glands of the Dog



5 Bulbis glandis (dog only)
Bulbis glandis (dog only) Responsible for the tie or coital lock Penile spines (tom only) Responsible for inducing ovulation Dependent on testosterone production Find penile spines picture


7 Dog reproduction Estrus length 7-13 days Ovulation type Spontaneous
Breeding days from start of estrus Gestation days Litter size Litters / year 2 Weaning weeks

8 Reproduction Estrus every 6-8 months Estrus lasts 21-22 days
Ovulation about 10th day Pseudopregnancy common

9 Canine Estrous Cycle Stage Duration in days External signs Proestrus
4-14 (9 days) Enlarged Vulva w/ bloody discharge, restlessness, no courtship w/ male Estrus 4-21 (10 days) Clear to pink vulva discharge, female turns hindquarters towards him, raises pelvic region, waves tail, male acceptance and courtship Diestrus 60 Vulva shrinks, no discharge, non-acceptance of male, terminates with parturation Anestrus 100 + Inactive ovaries, no vulva discharge, low steroids

10 Ovarian Cycle is Divided into Four Stages
A. Pro-estrus 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. Behavior - bitch is restless and secretes pheromones but is aggressively negative towards male becoming more passive towards start of estrus B. Estrus Vulva swelling will soften and discharge will be slightly pink to straw- colored. Some females will still have a bloody discharge in estrus which is normal. Vaginal cytology will have a high concentration of cornified epithelial cells with little debris. Behavior - bitch seeks male turns hindquarters towards him, raises pelvic region, waves tail to one side and finally stands for mating by male.

11 C. Metestrus D. Anestrus Pseudopregnancy
Loss of vulva swelling and no discharge. Vaginal cytology is no cornified cells and high numbers of White Blood Cells. Behavior - non-acceptance of male D. Anestrus Period of ovarian inactivity and no vaginal discharge Will not return to heat again until at least 4 months Pseudopregnancy Extension of metestrus period in which progesterone concentrations remain elevated. Female will have nest building behavior and enlarged mammary glands.



14 Provides sexual posturing
Changes During Estrus of Bitch Vulva Swollen and Enlarged Bloody discharge from vulva Copulation Aggressive towards Male Passive Provides sexual posturing to male for copulation Proestrus Estrus Indicates Day of Peak in LH

15 Follicular Development

16 Ovulation: Ova are released from the follicles approximately two to three days following initiation of LH surge. Fertilization: Ovulated ova are not ready for fertilization (must complete Meiosis I) and therefore are not fertilized until Day 4 to 7 following the LH surge.

17 LH Peak The greatest number of ovulations occur 24 to 72 hours after the LH peak. Breeding can be timed from the LH Peak to the fertile period 4 to 7 days later. Plasma Progesterone (P4) Plasma P4 concentrations rise prior to ovulation - follicles will start luteinization before ovulation Measurement of serum P4 can be used as a means to determine day of ovulation and breeding - can be highly variable

18 Hormonal Patterns During Estrous Cycle
of Bitch Fertile Period Ovulation Fertilization Estrogen Completion of Meiosis I Arbitrary Plasma Concentrations Progesterone LH Days from LH Peak

19 Control of Estrus in the Bitch
A. Androgens Mibolerone Mode of Action: Administration: B. Progestins Ovaban (UpJohn) - Methytestosterone Negative feedback on FSH and LH Initiate 30 days prior to expected onset Proestrus (Schering) - Megestrol Acetate - Negative feedback on FSH and LH Depends upon stage of estrous cycle. Lower dosage needed if given 7 days prior to proestrus. A much larger dosage is needed to block ovulation if given during proestrus.

20 Induction of Estrus GnRH Administration: Estrus induction can be used to treat bitches that fail to cycle or have silent heats. Response of fertile estrus is highly variable. Anestrus is the result of low FSH and LH. GnRH can be used to successfully induce estrus in the bitch. However, it requires frequent (every 90 min) administration over 10 to 11 days. Specialized infusion pumps (mini-pumps) can be utilized to deliver the pulses of GnRH GnRH analogs can be used to induce fertile estrus in the bitch without giving frequent injections.


22 Intromission by vigorous thrusting of the hindquarters.
Breeding Intromission by vigorous thrusting of the hindquarters. Swelling of bulbus glandis swells (6X4 cm) in the vagina Vulva sphincter muscles contract around the penis forming the copulatory “tie”. First Stage of Coitus The “Turn” Second Stage of Coitus

23 Hormone Concentrations During Pregnancy and Parturition
Mating Prolactin Progesterone Corticosteroids Arbitrary Plasma Concentrations Total Estrogens Days of Pregnancy

24 Pregnancy Diagnosis A. Abdominal Palpation B. Radiography C. Ultrasonography Day 25-32 Day 42 Day 21

25 Signs of Impending Parturition
Behavior of bitch is one of 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 is a consistent sign of impending parturition. Presence of milk in mammary gland is not an accurate sign. Decrease in body temperature from 38 to 37oC just before parturition.

26 Parturition First Stage of Labor
Averages 4 hours but can last 6-12 hours Period in which the cervix dilates Bitch will be uneasy, refuse food, pant, vomiting and frequently looking at flank. Second State of Labor Visible straining of bitch in the sitting position Placental membrane will break and there will be fluid discharge from vulva. Membrane will rupture spontaneously or through licking of dam. After the start of labor first fetus cannot be expected to survive more than 6 hours in the uterus. Fetuses should be delivered within 2 hours of each other. Usually interval between puppies is about 30 minutes.

27 Third Stage of Labor Passage of fetal membranes should take 5 to 15 minutes. Dystocia Definition: Any problem with delaying normal birth of fetus. Symptoms Abnormal fetal presentation, position or posture Strong and persistent labor for 20 minutes without delivery of fetus. Weak and infrequent contractions for 2 to 3 hours More than 4 hours from delivery of last fetus (if not last one) Most common problem is uterine inertia (weak contractions), size of fetus and birth canal.


29 Contraception in Bitch
Surgical: Physical: Intravaginal Device Silastic and polyethylene tubing placed in vestibule and vagine. 50% of bitches can still tie and get pregnant. Adding copper ring increases effectiveness Hormonal: Progestogens : Medroxyprogesterone - MAP Megesterol Acetate – MGA Androgens : Implants – Mibolerone Immunological : Immunize against LH Anti-ZP3 - anti-zona vaccine Ovariectomy Hysterectomy Tubal Ligation

30 Contraception in Male Surgical : Chemical Agents : Immunization :
Castration - Correct behavior such as wandering fighting, and urine marking Vasectomy - Tie Vas Deferens Chorhexidine - injected into epididymis Immunize against LH


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