PROFESSIONALISM “No man ever reached to excellence in any one art or profession without having passed through the slow and painful process of study and preparation.” -Horace

THE REPRODUCTIVE SYSTEM THE ESTROUS CYCLE

NORMAL ESTOUS CYCLE: THE BITCH Estrous Cycle: Defined as the time from the beginning of ________________ at period to the beginning of the next. Onset of puberty: 6-24mths; Avg.: _________________

ESTROUS CYCLE Proestrus : leading to __________ (Avg: 9-10 days) Estrus: ______________ (Avg: 9-10 days) Metestrus: 2 phases in ________________ Diestrus: _________________ is established (Avg: 57-58 days) Anestrus: time when _______________________________ (Avg: 2-5 months) PAGE 374 (Figure 14-1)

Causes GnRH release > LH surge HORMONE Hypothalamus GnRH Anterior Pituitary FSH Ovarian Follicle Estrogen Causes GnRH release > LH surge

HORMONE CHANGES

Typical morphological features of the vaginal mucosa and endometrium in anestrus (A), proestrus (P), estrus (E), and early diestrus (D). H&E. Original magnification 200X.

PROESTRUS PROESTRUS: the period when the bitch is _______________________ active, but __________ the male’s advances Physical signs of proestrus: _______________ vaginal discharge Vulvar swelling Vaginal edema Internal physical signs: Lengthening and hyperemia of the uterine horns Enlargement of the cervix Thickening of the vaginal wall

PROESTRUS http://www.vetmed.wisc.edu/data/coursematerial/bosu/CR-lecture1and2.pdf

PROESTRUS Hormonal signs of proestrus: Increasing serum concentrations of ______________ (estrogen) estrogen is responsible for the physical signs of proestrus Estrogen is being produced by the maturing follicles in the _______________ (under the influence of Follicle Stimulating Hormone or FSH) As proestrus progresses, the estrogen levels begin to peak and initiate the onset of estrus.

PROESTRUS Cytologic signs of proestrus: Vaginal Cytology _______________________ and intermediate cells predominate; wbc’s and rbc’s present Duration of proestrus: 3-17 days; Avg.: 9 days

VAGINAL CYTOLOGY Part the lips of the vulva and gently insert a swab at a relatively steep angle. Some people suggest using a speculum (e.g. the cone from an otoscope) and some like to moisten the swab with saline prior to use, but neither of these is critical. After 1-2 inches of the swab have been inserted, the angle of insertion can be altered to roughly 45 degrees and insertion continued.

VAGINAL CYTOLOGY

VAGINAL CYTOLOGY

PROESTRUS INTERMEDIATE CELLS RED BLOOD CELLS

THE NORMAL ESTROUS CYCLE: ESTRUS ESTRUS: The period of _______________________ of the male Physical signs of estrus: The swollen vulva is __________________ The vulvar discharge is usually ____________ bloody The bitch allows mating “standing” heat “flagging” behavior (tail deviated to the side)

ESTRUS http://www.vetmed.wisc.edu/data/coursematerial/bosu/CR-lecture1and2.pdf

ESTRUS Hormonal signs of estrus: Serum estrogen peaks in late proestrus and early estrus. The estrogen peak initiates a surge of ________________________________ LH results in ovulation (rupture) of the mature follicle and release of the oocyte. LH also stimulates the cells left behind in the empty follicle to multiply into the corpus luteum (See metestrus) serum _________________________________ levels begin to increase toward the end of estrus (and beginning of metestrus) Progesterone is produced by the corpus luteum which is forming from the _____________________ follicle (see metestrus) Progesterone is the hormone that maintains __________________________________________________

ESTRUS Cytologic signs of estrus: Vaginal cytology: Superficial and superficial ____________________________ predominate (aka cornified cells); rbc’s usally present, wbc’s ___________________________ Duration of estrus: 3-21 days; Avg.: 9 days

ESTRUS: VAGINAL CYTOLOGY CORNIFIED EPITHELIAL CELLS

METESTRUS METESTRUS: The period _________ ovulation when the ________________ develops. Internal signs of metestrus: Lining of the uterus is ______________________ and “juicy” in preparation for implantation of a fertilized ovum Loss of the cornified epithelial lining that developed in the vagina during proestrus and estrus

METETRUS

DIESTRUS DIESTRUS: the period when the corpus luteum has reached ________________ size and _______________ . Begins with the bitch’s _________ to mate Physical signs of diestrus: None except the cessation of signs of estrus Hormonal signs of diestrus: Serum _______________________ levels continue to increase and peak during diestrus In a pregnant bitches, there is a rapid pre-partum drop in progesterone ~ _____________ hours before parturition In non-pregnant animals, the decline may be more gradual

DIESTRUS Cytologic signs of diestrus: Duration of diestrus: ~2mths Vaginal cytology: A sudden __________________ in the number of superficial cells and a reappearance of intermediate and parabasal cells, and wbc’s. Duration of diestrus: ~2mths Dogs and cats are unique in that their corpora lutea appear to have _______________________ life spans.

DIESTRUS: VAGINAL CYTOLOGY INTERMEDIATE CELLS PARABASAL CELLS

DIESTRUS PSEUDOPREGNANCY: A prolonged ______________________ Animal may show signs of pregnancy: Nesting behavior Mammary enlargement Lactation in extreme cases Clinical signs ______________ with time

ANESTRUS ANESTRUS: Follows ___________ and ends with the onset of proestrus; criteria vary First time plasma progesterone reaches a level below _____________ nmol/L The moment that the influence of progesterone on the ____________________________ is no longer evident. Cytologic signs of anestrus: Samples are almost ___________________ The cells present are _____________ and ______________________ cells. Duration of anestrus: Avg.: ~4.5mths.