vet-tech-therio-ch-10

• female gonads
• - hormones
• - reproductive cells
• paired oval glands
• abdominal cavity
• caudal to the kidneys
• produce eggs
• blood supply
• - ovarian artery
• - uterine artery
• release 2 hormones:
• - 1. estrogen - controls female characteristics
• - 2. progesterone - maintain pregnancy

• aka oviduct (birds, lower mammals) or Fallopian tubes
• transport oocytes to uterus:
• - 1. prepared for fertilization
• -- a. infundibulum
• -- b. muscle contractions, movement of cilia move oocytes down towards the uterus
• -- c. oocyte requires 2 days of maturation in the uterine tube before it is capable of being fertilized
• - 2. are fertilized
• - 3. 1st stages of embryonic development

• ovarian extremity of uterine tube
• opening where ova enter uterine tube from ovary

• aka "womb"
• houses developing embryos => fetuses
• y shaped
• 2 uterine horns
• - cranial end connected to caudal end of corresponding uterine tube near the ovary
• - length of horns much greater than diameter
• short body - connected to each horn
• neck (cervix) - channel, thick firm tissue between uterus and vagina (very tip or base)
• varies in size:
• - size and weight increase during estrous cycle (aka heat cycle)

• 3 layers
• - 1. serosa
• - 2. myometrium
• - 3. endometrium

outer, thin covering of peritoneum

• muscular portion
• metritis is inflammation of myometrium
• 2 layers:
• - 1. outer longitudinal
• - 2. inner, thicker, circular layer
• important during parturition

• inner, thickest layer
• glands, blood vessels

infected uterus

• aka "birth canal"
• musculomembranous canal
• opens caudally into vulvar area just ahead of the urethral opening
• vaginal mucosa undergoes dramatic changes during estrous cycle
• - vaginal cytology
• longitudinal and transverse folds
• - allows for expansion during mating, pregnancy and whelping

• aka labia (lips)
• form the external boundary of the vulva
• soft and pliable
• join ventrally to form a pointed projection that extends downward and backward from the body
• may change in size during the estrous cycle or pregnancy
• the only external part of the female reproductive system

• don't want to spay a dog in heat - want to wait 8-12 weeks
• will do cat in heat

• modified sweat glands
• two bilaterally symmetrical rows
• extend from ventral thoracic (chest) to inguinal (groin) region
• number of glands varies from 8-12 (4-6 on each side of midline)
• typically 10:
• - thoracic mammae - cranial 4
• - abdominal mammae - following 4
• - inguinal mammae - caudal 2

• period when the capability of reproduction is attained (first estrous)
• 5-18 months old
• depending on breed and sire (genetics)
• nutrition - poor nutrition can delay/stop estrous
• smaller breeds - earlier estrus than larger breeds
• most breeds:
• - 2 cycles per year
• - Basenji - 1 cycle per year
• - Collie - every 9 months
• - German Shepards - every 26 weeks

• aka "season"
• 4 stages:
• - proestrus
• - estrus
• - diestrus (aka metestrus)
• - anestrus (an = without)
• gestation for dog is ~63 days

• follicular growth
• bitch is attractive to male, but she will not allow mating
• predominant hormone is estrogen
• raised levels of estrogen cause:
• - production of pheromone that make female attractive to male
• - serosanguinous vaginal discharge ("blood spotting")
• - vulva becomes enlarged and protrudes
• - wall of vagina becomes swollen
• - increase in number of layers of cells of the epithelial lining of the vagina
• -- outer layers die and slough off
• - pituitary stops secreting FSH

• - bitch will accept dog's advances, allow mating
• - estrogen levels fall, progesterone levels rise which results in...
• - reduction in vaginal mucous swelling and edema
• - behavioral estrus
• -- "slipping the tail" - moving the tail to one side to allow intromission
• - ovulation of a follicle results in a corpus luteum (secretes progesterone)
• - different breeds of dogs will ovulate different numbers of follicles:
• -- bigger breeds have bigger litters
• - once ovulation and fertilization occurs, the bitch will stop accepting the male

• two month stage following estrus when the reproductive organs are under the influence of progesterone from the corpus luteum
• action of progesterone:
• - causes proliferation of uterine glands (to support muscular contractions for parturition) and support pregnancy

• period of rest
• reproductive organs are inactive
• preferred period to spay dog

• establish when ovulation takes place in order to coordinate mating with this event
• ways to determine:
• - 1. measurement of LH peak in peripheral blood
• - 2. character of vaginal mucosa
• - 3. vaginal epithelial cytology
• - 4. measurement of peripheral blood progesterone
• relied on vaginal cytology for years & estrogen levels (not particularly accurate)

• ovulation closely correlated with LH surge
• LH surge transitory - would need multiple blood samples every 10-15 minutes to not miss peak
• LH surge may happen on one day
• not practical

• Proestrus - vaginal mucosa is edematous, round, pink, glistening
• decreased estrogen levels, increased progesterone levels - mucosa becomes shrunken and wrinkled
• view hormonal changes - vaginoscope or endoscope

• cells can be anuclear, superficial, intermediate, parabasal
• see pic in slides

• most accurate method of predicting ovulation
• most used now
• progesterone levels begin to rise before ovulation takes place
• - unique to the dog
• - doesn't happen in the cat
• can do:
• - ELISA (Ovucheck PreMate (TM)) in house testing
• - outside laboratory testing
• - rarely performed in most practices, so usually outside lab

• 1. natural breeding
• - goal - achieve best conception rate and litter size with least labor and cost
• - one or more breedings (alternate days) during behavioral estrus ususally results in pregnancy
• 2. artifical insemination

• General physical exam
• - general health
• - reproductive system
• -- abnormal vulvar confirmation
• -- vulvar discharge
• -- digital (finger) exaination (>7 kg) for tumors, foreign bodies, abnormalities
• -- mammary glands - palpate for tumors, other abnormalities
• - current immunizations
• - testing for heartworm and other parasites - i.e. Brucella canis (brucellosis)
• - genetic testing for certain breeds, for example:
• -- hip/elbow dysplasia - shepards, etc
• -- heart disease - boxers, King Charles spaniels
• -- thyroid disease
• -- ocular conditions - collies

• takes place in the uterine tube (between ovary and uterine horn)
• early embryo is in the uterine horn (by 9-10 days)
• implantation doesn't occur immediately (occurs at about 19-20 days)

• progesterone - dominant hormone of pregnancy
• pseudocyesis (false pregnancy) - little or no difference in levels of progesterone in pregnant & non-pregnant bitch
• relaxin
• gestation length - ~63 days (56-72)

• pregnancy specific hormone produced by placenta and ovary
• rises gradually in the last 2/3 of pregnancy
• detectable from day 25 of gestation

act of giving birth

normal parturition

difficult parturition

• abdominal palpation
• - don't want to rely solely on this
• transabdominal ultrasonography
• transabdominal radiography
• - better (easier to) count than with ultrasonography
• - as long as its only 1 radiograph, it doesn't seem to be harmful
• peripheral blood relaxin levels
• doppler ultrasound
• transabdominal auscultation

• 3-4 weeks
• - individual fetal swellings can be palpated through the abdominal wall
• - "bumps" 12-15 m (~1/2 inch) diameter along the uterine horn
• 5-6 weeks
• - difficult to palpate pregnancy
• 6-7 weeks
• - can palpate fetuses due to ossification
• - can identify fetal heads
• - difficult to identify number of puppies

• 3 weeks and later
• - can detect fetal fluids and fetuses
• - can determine fetal heartbeat and viability of fetus
• most reliable method

• 6-7 weeks
• - can determine fetal skeletons
• - can detect fetal death due to skeletal degeneration and putrefying gases

• relaxin
• - pregnancy-specific hormone
• - begins to rise 21-26 days after conception

sound waves throught the abdominal wall are reflected at a different frequency when they hit moving fluid (blood in fetal umbilical veins or heart)

• stethoscope used late in pregnancy to hear fetal heart beats
• fetal heart rate is twice that of dam in both dog & cat

• aka whelping
• high levels of progesterone (maintains pregnancy) dampen the normal contractions of the uterus
• onset of parturition is initiated by luteolysis (corpus luteum) and reduction in the level of progesterone
• triggered by signals from the fetus
• raised levels of corticosteroids (ACTH) one day prepartum
• no raised levels of estrogen
• three stages of labor

• increased uterine muscle contractions
• lasts 6-36 hours
• preceded by drop in body temperature (BT) by 2 degrees (to 99 degrees)
• bitch appears restless and nervous, looking at flanks (esp first timers)
• looking for a quiet place to make a nest
• vagina relaxes and cervix dilates
• fetus rotates - head is pointing towards the cervix
• posterior presentation can be normal
• transverse presentation (across birth canal) is dystocia

• involuntary uterine & voluntary abdominal wall contraction and expulsion of the fetus
• completed within 3-12 hours
• lateral recumbency
• visible abdominal straining
• first puppy should appear within 2-hours
• STRONG abdominal straining puppy may appear within 20-30 minutes
• interval between each puppy should NOT be more than 2-4 hours
• expulsion of green fluid, "lochia" - allantochorionic fluid, "the breaking of the waterbag"
• bitch licks puppy to clean/dry, stimulate breathing

• expulsion of the placenta (fetal membranes)
• occurs within 10-15 minutes of the pup or may follow the birth of each pup
• leave the parturient bitch in peace (unless she needs you)
• +/- attend to neonate

• with C-section, puppies will almost always have some anesthetic effects
• amniotic memebrane may need to be broken (to allow puppy to breathe)
• vigorous rubbing dry and warm the puppy, stimulate breathing
• gently suck fetal fluids with a plastic pipette (or baby nasal bulb) that may be blocking airways (carefully swing puppy downwards)
• clamp umbilical cord with sterile forceps or cut to 4 cm with sterile scissors
• - +/- ligate cord with sterile absorbable suture
• +/- guide pups to nurse

• completed within 6 hours of second stage labor
• >12 hours considered abnormal
• prolactin levels rise (triggers lactation)
• suckling by the puppies stimulates oxytocin release - initiates milk letdown

• during pregnancy:
• - mammary glands develop in response to gradual increase in levles of prolactin
• parturition:
• - progesterone levels drop
• - prolactin levels rise
• lacation last for about 6-9, prolactin levels remain elevated
• maintenance of lactation also requires cortisol and insulin

• primary uterine intertia
• - failure to expel normal-sized fetuses through a normal birth canal
• - incompletely dilated cervix
• secondary uterine inertia
• - prolonged uterine contractions fail to expel a fetus
• - obstructing birth canal
• breed
• - brachycephalic breeds: broad head, narrow pelvis, C-section
• confirmation
• - congenital/acquired abnormalities:
• -- old healed fractured pelvis
• -- vaginal prolapse - common in boxers
• -- vaginal neoplasia

• presentation, position, posture
• abnormal fetal development
• - fetal monsters
• - hydrocephalic puppies
• - multiple limbs
• - abdominal and/or thoracic hernia
• partially delivered puppy - stuck in birth canal

• 1. removal of puppy manually
• 2. medical treatment - oxytocin - to increase uterine contractions
• 3. Cesarean section
• 4. Eclampsia - low calcium levels - can cause convulsions/coma in mom

• aka false pregnancy
• some non-pregnant bitches may lactate weeks after their heat cycle (season)
• lactation in the abscence of pregnancy
• does not show signs of pregnancy (Sheila disagrees - has seen nesting behaviors)
• may be caused by a steep drop in progesterone or greater sensitivity by some animals to the normal decline...
• - ...causes the release of prolactin and the induction of lactation

• spaying
• interruption of behavioral estrus
• induction of estrus
• treatment of pseudosyesis
• termination of pregnancy
• induction of milk letdown
• induction of parturition
• most of these mess with hormones

• ovariohysterectomy (OHE) - surgical removal of the ovaries and the uterus
• in Europe often doing ovariectomy
• - smaller incision, faster surgery
• - no medical reason to do it this way
• - can still get pyometria this way

administration of oral or injectable progesterone to block the production of follicle stimulating hormone (FSH)

administration of anti-prolactin to supress luteinizing hormone (LH) and follicle stimulating hormone (FSH) secretion

can treat lactation in the absence of pregnancy with progesterone (aka anti-prolactin) - preferred treatment

• administration of a specific anti-progesterone
• removal of the corpa lutea which produce progesterone
• - use of anti-prolactin
• - prolactin necessary to support the corpus luteum
• combination of anti-progesterone and anti-prolactin

• mammary gland development, but no milk being secreted
• administer oxytocin

• administer corticosteroids
• this stimulates the production of enzymes
• convert progesterone to estrogen
• increases uterine contractions
• triggers parturition
• to start this, need:
• - viable placentae
• - uterine myometrium capable of contraction
• - to be close to term