Feline Theriogenology Flashcards
What gender and breed of cat is commonly associated with genetic disorders? What is seen?
male tortoiseshell cats
39XXY or 38XX/XY (chimera) - born with poor sperm quality causing sterility
- 38XX/XY have a possibility of being born fertile
- X chromosome is responsible for coat colors, 3 X’s = white, black, orange
When do cats go into puberty? What 4 things affect onset?
4-12 months (mean of 9)
- time of year - summer born earlier (5-6 months) compared to spring born (12 months) to reach long days
- body condition - ~80% bodyweight
- breed - oriental breeds < Persian, Manx, DSH < DLH
- environment - free-roaming, ferals < domestic, males < females
When is it recommended to breed cats? Why?
no cats younger than 12 months
sexual maturity is reached before physical an behavior maturity —> by the time of puberty, cats will still be growing and unable to handle a pregnancy = increased chance of dystocia
What 4 things should be performed in pre-breeding evaluations?
- keep up to day on vaccines
- test for FeLV and FIV before introduction into catteries
- test or treat for internal/external parasites
- test for inherited diseases - polycystic kidney disease in Persians
What is the importance of blood typing prior to breeding cats?
prevent neonatal isoerythrolysis when a type B queen is bred to a type A tom
What type of diet should be avoided in a breeding cat?
raw meat —> toxoplasmosis
What is indicative of feline neonatal isoerythrolysis? Why does this occur?
fading kittens - acutely ill kittens following ingestion of colostrum
type B queen bred to a type A tom —> Type B queen has high ant-A antibody levels
What clinical signs are indicative of neonatal sioerythrolysis?
- anemia
- icterus
- hematuria
- tail tip necrosis
- sudden death
fading kittens
What type of seasonal breeders are cats? What does this mean?
long day - Jan-Oct with peak estrous activity Feb-Apr in the Northern Hemisphere
require at least 12 hours or more of natural/artificial light to maintain normal cyclicity —> melatonin secreted by pineal gland
- indoors = constant light = constant cycling
What happens when the proper amount of light for cycling in cats is not achieved?
<8 hours = cyclicity abruptly stops
What kind of ovulators are cats?
polyestrous, induced ovulators
What are the 5 stages of the feline estrous cycle?
- anestrus
- proestrus
- estrus
- interestrus/postestrus - period between one estrus and the next in queens that have not ovulated as more follicles are being produced
- diestrus
What is anestrus? What are the 3 major causes in cats?
absence of cycling activity with baseline concentrations of sex hormones
- seasonal - Oct-Dec with inadequate daylight length
- lactational - 2-3 weeks after weaning
- pathological - primary anestrus = failure to show first estrus by 24 months (DSD, karyotyping)
What is a silent heat? How is it diagnosed?
timid or intimidated queens in different environments leading to periods of anestrus
evaluation of vaginal cytology once or twice weekly
Proestrus is difficult to detect in queens. How long does it occur? What are 4 subtle signs?
1-2 days
- rub head and neck against convenient objects
- display affectionate behavior
- mucoid vulvar discharge and pollakiuria
- female is attractive, but not receptive to males
When are queens sexually receptive? What are 5 behavioral changes seen?
estrus - 1-16 days —> average of 7 days, week on and week off
changes more pronounces compared to proestrus:
- persistent vocalization
- rolling, rubbing
- tail deviation
- lordosis
- repeated, monotonous howling
What change is not seen when queens are in estrus?
no changes in the appearance or size of external genitalia
What is interestrus/postestrus in queens? How long does it typically occur?
if no ovulations occur, the queen cycles into estrus on an average of every 2-3 weeks —> week on, week off
2-19 days —> 7 days on estrus
What can prolong interestrus/postestrus in queens? What signs are seen at this point?
24-hour light schedule —> more light uses up more of the follicular reserves
no sexual behaviors
What triggers ovulation in queens? How?
induced —> copulation or mechanical stimulation (can still spontaneously happen)
stimulation of caudal vagina causes a release of LH (surge!)
What does ovulation in queens depend on? How does this occur post-coitus?
adequate amplitude and duration of LH
- LH surge within minutes of coitus and peaks 1-2 hours
- ovulation occurs within 24-48 hours (works for the first time in 50% of cases)
- multiple copulations (~4) results in higher levels of LH
What 2 things occur during feline copulation? What results in males and females?
- neck biting and mounting (10s - 30m) - tom grasps skin of neck with teeth
- intromission and ejaculation (1-27s)
- MALE = dismounts quickly and retreats from queen
- FEMALE = strikes out at male, disoriented rolling, stretching, and genital licking
How is successful mating observed?
post-coital reaction of the queen
- NOT just mounting
What are the 2 major strategies of breeding management in cats?
- natural breeding
- artificial insemination - vaginal, transcervical, surgical - requires ovulation induction (caudal vagina, deposition is not enough)
What 2 methods are preferred for natural breeding in cats? Why?
bring queen in estrous into male’s established territory and…
- breed ad libitum for short periods during the first 3 days of estrus
- breed the queen 3 times daily on the 2nd and 3rd day of estrus
housing the queen and tom together during the queen’s estrus can deplete sperm reserves
What is avoided when naturally breeding cats?
matching 2 inexperienced cats
What is the reproductive tract of queens like in diestrus? How long are their pregnancies?
preovulatory follicles become corpora lutea and secrete progesterone (luteal phase)
~65 days
What causes pseudopregnancy in cats? When does this occur?
unfertilized oocytes or early pregnancy loss
diestrus - CLs only last 40 days due to decreased levels of P4 that happens sooner with no pregnancy
What is not seen in pseudopregnancy in queens? What happens when it passes?
maternal behavior or lactation
estrus may resume in 10 days after the end of the luteal phase
Queen estrous cycle:
When does pyometra occur in queens? What is it associated with?
diestrus
cystic endometrial hyperplasia-pyometra complex
In what queens is cystic endometrial hyperplasia-pyometra complex most common? Why does this occur?
older queens (~7 y/o) in estrus within 4 weeks
progesterone is aggravated by estrogens, (prime the endometrium, increasing progesterone receptors), resulting in endometrial glandular proliferation and enlargement as well as distention of the endometrial glands with secretions
What are the most common signs of CEH-pyometra complex? How is it treated?
- vulva discharge (open cervix)
- lethargy, anorexia
- abdominal distention
- dehydration, PU/PD
- pyrexia
surgery and aggressive medical treatment
What is fibroadenomatous mammary hyperplasia? What is it associated with?
non-neoplastic, localized, non-painful swellings of one or more mammary glands in diestrus (occasionally in pregnant queens) most common in young, intact females following first or second estrus
progesterone hypersensitivity to physiological concentrations or males/females receiving exogenous progestagens
Is treatment commonly necessary for fibroadenomatous mammary hyperplasia? What 3 treatments can be used?
no - typically regresses with decreased progesterone levels
- Carpergoline
- spay to remove source of progesterone
- PGF2a
When does the embryo enter and implant in the uterus?
ENTER = 5-6 days post-coitus
IMPLANTATION = day 13-14
What is the average litter size in cats? Gestation? How does litter size affect gestation?
4 —> more with larger breeds, like Maine Coons; produce largest litter during 2nd parity
65 days —> longer in Oriental Shorthairs, shorter in Korats
larger litter = shorter gestation
What are 3 ways of diagnosing pregnancy in queens?
- absence of estrus at 21 days - not specific, indicates that ovulation occurred (can be pseudopregnancy, ruled out after 40-50 days)
- behavior - increased docility, excessive grooming of perineal region and mammary glands, and nesting during late pregnancy
- physical - increased BW, increased size and reddening of nipples (>21 days), mammary gland enlargement and colostrum (>58 days)
What is a more definitive way of diagnosing pregnancy in cats? What is the optimal timing?
manual palpation - should be only discrete tissue mass between colon and urinary bladder (can be a pathologic dilation with pyometra)
between 21 and 25 days after mating
When can ultrasonography be used to diagnose pregnancy in cats? What 3 things can be done? What cannot be done?
14-15 days post-coitus until term
- monitor fetal HR, normally >200 bpm
- identify developmental abnormalities
- fetal biometry between 25 and 35 days post-coitus to predict due date (decreased accuracy as pregnancy progresses)
determining litter size
What is the best way to determine litter size in cats?
radiographs —> by 45 days post-coitus, bone mineralization should occur
What bioassay can be used for pregnancy diagnosis in cats? Why is this useful?
serum relaxin levels
relaxin is produced in the placenta, so it will not be seen with pseudopregnancy
Why is proper nutrition especially important for pregnancy queens? What 2 practices are recommended?
the queen will gain weight linearly from conception to parturition
- increase food intake by 10% per week throughout pregnancy so that they should be consuming 70% more energy by the end
- small meals several times per day
What deficiency especially needs to be avoided in pregnant queens? Why?
taurine - not as common now with balanced commercial diets
can cause resorption or abortion of fetuses or the birth of kittens with low birth weights and developmental abnormalities
What behavior is especially common in queens 1 week before delivery? What preparations are necessary as birth date approaches?
nesting - should provide a kittening box lined with absorbent bedding
- towels
- thread to tie off umbilical cords
- syringes for suction
- access to veterinary assistance
What 3 activities occur in queens with impending delivery?
- within 24 hours, rectal temperature drops one full degree (<99 F)
- progesterone may remain stable at 3-5 ng/mL
- milk in mammary glands
When do most queens give birth?
at night, unattended
What 3 things occur during stage 1 of labor in cats?
- no visible contractions, but queen becomes restless, overgrooms, paces, pants, may vomit, or not eat for up to 24 hours before
- cervix dilates and uterus starts contracting
- clear to slightly reddish brown mucous discharge from vagina
(6-12 hours, nervous primiparous at 24 hours)
What occurs within stages 2 and 3 of labor in cats? When do most queens complete?
active abdominal contractions and fetus expulsion within <60 mins and more following every 30-60 mins
within 6 hours
(4-16 hours, can be up to 42 if queen stops)
How are kittens born? What happens if the queen is disturbed in early stage 2?
both head-first (cranial, 70%) and hind-first (caudal 30%) are normal with interspersed delivery of placentas where the queen may eat them
can suspend delivery for 2-3 days without apparent complication
What is considered prolonged gestation in queens? What 4 things can be seen?
more than 71 days from the last breeding where no kittens are produced after 3-4 hours of stage 2 labor
- 30 mins of strong contractions without delivery
- more than 2 hours between kittens
- failure to deliver all kittens within 36 hours
- abnormal vulvar discharge - profuse brown-red bloody discharge with a foul odor indicating the beginning of placental separation
When is medical treatment of dystocia contraindicated?
obstruction of the birth canal
- uterine torsion
- fetal oversize
- abnormal fetal disposition
What is the most common sign of dystocia? What treatment is recommended?
fetal stress - HR <150-160 bpm
Cesarean section
What are 3 predisposing factors associated with dystocia?
- dolichocephalic
- brachycephalic
- smaller and larger than normal litter sizes
What 2 things happen postpartum in queens? What should be monitored?
- appetite returns within 24 hours
- scant post-partum discharge (lochia)
- abnormal vulvar discharge
- fever, anorexia
- kitten neglect
- mammary glands (swelling, redness, heat, pain)