Canine Reproduction

Canine Reproduction Rigs

Oestrus Cycle In the bitch       

Monoestrus Ovulating once or twice 5-12 mo intervals Puberty-Female 6-24 mo Smaller breeds-6-10mo Larger breeds 12-24 mo Male-6-9 mo

Oestrus Cycle         

One oestrus period in the cycle Inter oestrus interval Variable 5-10 mo 5 phases Pro oestrus-9d Oestrus-10d Metoestrus 3-5d Dioestrus 65d Anoestrus 120d Pregnancy 64d

Pro-oestrus 

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1st day of BLOOD discharge to 1st day of acceptance of male 2-12 d ave:9d Increased gonadotrophin secretion Follicular development & estrogen secretion Estrogen prepare the Vagina Cervix & Endometrium fro bleeding

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Rapid increase in vaginal cell layers for basal and germinal cell proliferation Increase the cell layers from the blood suply cell death occur Cornified and Keratinized cell Reach peak toward the end of the pro-estrus

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Changes in the Uterus Cell proliferation –increase the thickness, Hypertrophy and vascular supply Bleeding from endometrium occur Vaginal bleeding

Behavior      

Exitable and restless Loose appetite Increase water intake Frequent urination Attractive to the male Do not allow to penetrate

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Vaginal cell smear-Cornfield squamous cells + RBC, Parabasal cells, Large intermediate cells

Oestrus    

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Period of sexual receptivity 2-18 d ave 10d 1st day of acceptance to refusal Declining of Estrogen-starts 1-2 d prior to the estrus Rise in Progesterone-72-96 hrs prior to the ovulation LH serge and oestrus behavior

Behavior     

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Stance for mating Expose vulva-arch back Vulva become soft and flacid Straw or pink vaginal discharge Do not allow to penetrate until vulva become soft and flaccid( first 1-2 d) Vaginal smear-anuclear squamous epithelial cells 80-100% with few RBC & WBC

Metoestrus   

3-5d Formation of corpus luteum Start progesterone secretion

Dioestrus    

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Starting from refusal of male to… Pregnant-until whelping Non-pregnant-demise of CL 60-80d High progesterone; reach peak at 20-3- d post ovulation; transient platue 7-14 d; slowly decline in next 10-20 d; abrupt decline near whelping Estrogen remains basal LH FSH few episodes

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During 1st few days vulval discharge reduce rapidly Vaginal smear-Superficial epithelial cells, RBS, WBS Progesterone does Uterine hypertrophy and Vasculature, glands Pseudopregnancy

Anoestrus  

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4-5mo Uterine involution Transition from dioestrus to anoestrus is not externally distinguishable Low level of progeatorone, LH FHS, Prolactin Lactating bitches Prolactin remains elevated Vaginal cell smear-epithelial cells, parabasal cells, few WBC, NO RBC

Luteal maintanance    

LH and prolactin Independent in 1st 10 days Then both LH and Prolactin After 42 d more on prolactin

Luteolysis 

PGF 2Alpha