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Normal anatomy of the queen
- two ovaries
- uterine tubes
- uterus
- cervix
- vagina
- mammary glands
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Ovaries
dorsal (back) abdomen caudal to the kidneys
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Uterine tubes
- fallopian tubes/oviducts
- transport channel for ova between the ovaries and the uterus
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Uterus
- Y-shaped
- 2 uterine horns, uterine body
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Cervix
thick-walled neck of the uterus connecting it to the vagina
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Vagina
- extends caudally from the cervix
- ends in the outermost portion fo the reproductive tract, the vulva (not as obvious in cat, even in heat)
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Mammary glands
- 4 pairs
- - 2 bilaterally symmetrical rows (ventral thoracic to ventral abdominal)
- - right and left axillary (armpit), thoracic, abdominal and inguinal
- - right and left mammary glands 1, 2, 3, and 4 (axillary to inguinal)
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Female cat is seasonably polyestrous
- having estrous cycles during only part of the year
- stimulated by increase in daylight
- 16 hours daylight, will cycle throughout the year
- can become pregnant again soon after parturition
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Spontaneous ovulation
triggered by visual or pheromone
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Induced ovulator
- ovulation is triggered by the act of mating
- - once egg is released it is ready to be fertilized
- - needs to be stimulated to release egg
- in the absence of mating, the mature follicle regresses without ovulating
- * different from the bitch
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Puberty
- 4-18 months; usually 6-9 months
- spay recommended 5-6 months
- variation depends on:
- - body weight - 2.3-2.5 kg (approx 5-6 lbs) in weight
- - time of year - increasing daylight (winter may delay)
- - breed - genetics
- - nutrition - starvation will slow
- long reproductive life
- - often exceeds 14 or more years
- - litter size may be reduced as queen ages - less eggs are ovulated
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Feline Estrous cycle
- pro-estrus
- estrus (behavioral estrus)
- interestrus
- anestrus
- can/will spay cat in heat
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Pro-estrus
- difficult to detect
- first few days of heat, queen is calling but will not accept male's advances
- ovarian follicles are beginning to grow, estrogen levels still low
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Estrus (behavioral estrus)
- period (3-7 days) when the female will accept the male (tom)
- follicles are mature, maximum level of secretion of estrogen from the follicles
- raised levels of estrogen are necessary to:
- - induce estrus behavior
- - prime the anterior pituitary for the luteinizing hormone surge that causes ovulation
- in the absence of mating, the follicles regress, estrogen levels fall, estrus suddenly ceases and the queen will stop calling
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Interestrus
- shorter than anestrus - fine line between the two
- period between one estrus and the next
- absence of mating ... will come into season every 10-14 days
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Estrous cycle
~21 days long... 7 days of proestrus and estrus, plus 14 days of interestrus
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Anestrus
- period during the winter where there is no ovarian activity
- melatonin (pineal gland)
- - secreted during the hours of darkness
- - suppresses the release of gonadotropin releasing hormone (GnRH) from the hypothalmus
- - the anterior pituitary gland does not release follicle stimulating hormone (FSH) and luteinizing hormone (LH) that would stimulate the ovaries
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Pro-estrus/early estrus
- attracts male will vocalization and estrus odor - does not allow mating
- may allow mating from several toms when she is receptive
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Ovulation
- sucessive matings are important to trigger ovulation
- vaginal stimulation at mating causes:
- - reflex release of GnRH from the hypothalmus
- - triggers luteinizing hormone (LH) release from the anterior pituitary
- - LH is primed by the raised estrogen levels in estrus
- - successive matings induce higher and higher peaks of LH until the ovulatory surge of LH occurs
- successive matings must occur in a short period of time to avoid drops in LH levles (ovulatory peak not achieved)
- LH surge lasts longer after multiple matings:
- - optimum levels obtained if there are 4 matings within 2-4 hours
- can occur without a mating taking place:
- - physically induced by stroking the back and tail
- - cats kept in colonies - pheromonal activity, activity of other females
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Ovulation rate
- number of follicles ovulated varies
- after ovulation, the queen goes out of estrus in 24-48 hours and a corpus luteum develops on each ovary
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Ovulation without fertilization
- after ovulation:
- - corpus luteum forms and produces progesterone
- - will continue to develop in absence of fertilization for ~25 days - pseudocyesis
- - life of the corpus luteum: non-pregnant cat shorter, dog longer
- - after regression of the corpus luteum, short interestrus period, hormone levels fall back to normal
- - FSH levels begin to rise again, queen will come back into heat (breeding season)
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Fertilization
- can be fertilized immediately after ovulation
- in uterine tubes (Fallopian tubes)
- early embryos pass into uterine horns at 4-5 days
- implantation occurs after 12-16 days - embryos evenly distributed in both uterine horns
- gestation period - 64 days
- corpus luteum - sole source of progesterone
- day 20-30 placenta begins to produce relaxin (supports corpus luteum)
- prolactin levels increase day 25-35 as relaxin levels are rising
- - prolactin is luteotropic - helps to maintain corpus luteum
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Pregnancy diagnosis
- abdominal palpation - at 3-4 weeks and after 6-7 weeks of gestation
- transabdominal ultrasound
- radiograph
- relaxin levels
- - pregnancy hormone
- - produced by placenta
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Feline parturition
- onset of parturition requires a live fetus
- - secretions from fetus triggers a cascade of events leading to parturition
- divided into 3 stages
- usually complete within 6 hours of the onset of second stage labor
- - should not be allowed to continue for more than 24 hours
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First stage labor
- onset of increased uterine contractions
- 6-12 hours, up to 36 hours
- abdominal straining, queen will appear restless and uncomfortable
- pre-parturient drop in BT not as obvious as in bitch
- progesterone is converted to estrogen (by corticosteroids from fetus)
- increased estrogen levels cause increased myometrial contractions leading to onset of parturition
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Second stage labor
- begins when abdominal straining starts/becomes more pronounced
- fetus in the pelvic canal - chorioallantoic membrane may rupture (reddish-brown fluid)
- fetus expelled within amniotic membrane
- queen breaks membrane, cleans newborn (neonate)
- queen bites through umbilical cord
- first kitten is usually expelled within an hour of second stage labor beginning
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Third stage labor
- expulsion of fetal membranes - placenta
- usually follows fetus within 15 miuntes
- 2 or 3 fetuses may be born before placenta(s) appear
- queen will often eat the placenta (may induce vomiting and diarrhea - V & D)
- leave the queen to kitten in peace - check quietly once in a while to make sure everything's okay
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Care of the normal queen
- delivered easily (usually)
- queen's appetite returns within 25 hours after parturition
- nursing queen - appetite may increase 2-4 times
- colostrum produced by queen for 24-72 hours postpartum
- queen may not leave kittens for 24 hours postpartum
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Postpartum disorders of the queen
- retained placenta (oxytocin - make uterus contract)
- uterine prolapse - uterus outside body
- metritus
- - inflammation of the uterus
- - depression, anxiety, fever, neglect of kittens, sanguineous or purulent discharge
- mastitis
- - inflammation of the mammary glands
- - warm, painful mammary glands; BT 103.5 - 106 degrees
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Disorders of pregnancy
- infectious agents
- - feline leukemia virus (FeLV)
- - feline immunodeficiency virus (FIV)
- - feline herpes virus
- - feline infectious peritonitis (FIP)
- - panleukopenia
- - chlamydia
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Feline leukemia virus (FeLV)
- "unfriendly disease"
- embryonic reabsorption, fetal abortion, birth of infected kittens
- viral particles cross placenta
- test before breeding
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Feline immunodeficiency virus (FIV)
- "friendly disease" - how its transmitted
- transmitted in semen
- passed transplacentally, nursing or grooming
- stillborn kittens, arrested fetal development, abortion, delivery of FIV infected kittens
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Feline Herpes virus
- abortion, fetal death, placental necrosis, persistent infection in kittens
- transmitted via respiratory secretions
- vaccinate for herpes (all breeding animals)
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Vaccination of pregnant queen
- do NOT vaccinate pregant queen for FVRCP
- can cause cerebellar hypoplasia in kittens
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Nursing assistance
- may need to break amniotic membrane
- - kittens need to gain oxygen via lungs once placental exchange of oxygen has been compromised
- fetal airways may be blocked with fetal fluids and mucus
- - clear airways from obstructions to allow breathing
- - gentle suction with a plastic pipette or gravity (carefully)
- may need to cut umbilicus
- - clamp with sterile forceps, tie with umbilical tape
- - 2 cm of umbilical cord should be left attached to the kitten to avoid an umbilical hernia
- - in C-section need to support forceps - can cause umbilical hernia
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Prevention of pregnancy
- prostaglandin
- - stimulate contractility of smooth muscle (abortion)
- prolactin antagonist - cabergoline
- - luteolysis
- - suppresses progesterone (abortion)
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Manipulation of reproduction
- induction of ovulation
- suppression of estrus - progesterone
- cats in colonies
- constant daylight length of 16 hrs
- - stops melatonin from suppressing hypothalmus, thus queens will come into season throughout the year
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The Tom
sexually active the whole year
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Puberty in the tom
- when the cat starts to produce spermatozoa in the ejaculate
- - 8-12 months old usually
- - 7-18 months
- penis begins to develop cornified pappillae
- - penile spikes - androgen dependent - develop as testosterone levels begin to rise
- - spikes regress rapidly following castration
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Reproductive organs in the tom
- testes
- spermatic cord
- epididymus
- vas deferens
- accessory glands
- penis
- prepuce
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Testes
- spherical, ovoid structures
- produce sperm (testosterone)
- descend into scrotum at birth
- - can retract into inguinal ring at will until about 4-6 months of age
- - worry if not descended by approx 8 months
- cryptorchidism - unilateral - descended testicle will produce spermatozoa
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Spermatic cord
- extends from deep inguinal ring to the testes
- comprises the ductus deferens, testicular artery and vein, etc
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Epididymus
site of sperm maturation and storage
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Vas deferens
excretory duct of the testes
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Accessory glands
- prostate gland, bulbourethral glands
- androgen dependent
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Penis
located ventral to the scrotum
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Prepuce
skin covering the free portion of the penis
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Mating
- rapid
- small amount (1 or 2 drops) of ejaculate (not fractioned)
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Secondary sex characteristics
- thickened skin on cheek pouches and scruff of neck caused by increased subcutaneous connective tissue
- - can bend 22 gauge needles
- more muscular appearance of male (anabolic steroid effects of testosterone)
- typical "tomcat odor"
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Manipulation of reproduction
- castration
- - removes the source of sperm and testosterone
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