Canine Breeding and Reproduction Flashcards
when is sexual maturity in dogs
-typically between 6 and 15 months
-first viable sperm production usually by 12 months
-varies breed by breed, smaller sooner
how often fo dogs have a estrous cycle
-usually 2x per year
-basenji and dingo 1x per year
-wolves cycle 1x per year
-late spring and early summer months
complete canine estrous cycle
-complete cycle takes 6 months in domestic dogs
-estrous semiannually
-estrus “heat”
-metestrus (diestrus)
-anestrus
how can heat cycles vary
-in length
-when they get their first heat
-how often
-within breed
things seen in different stages of heat cycle: proestrus
proestrus: ~9 days
-vulva swollen
-bloody discharge
-attracted to male but does not mate
things seen in different stages of heat cycle: estrus
~9 days 4-13 days
-accepts male
-straw coloured discharge
things seen in different stages of heat cycle: metestrous or diestrus
-non pregnant:
~90 days
-can have pseudo pregancy
-swelling goes down
-pregnant:
-pregnancy
-parturition 63 days from ovulation
things seen in different stages of heat cycle: anestrus
-2-5 months
-sexual inactivity
hormonal change of FSH
-goes up and then down during anestrus
-after its all the way down proestrus begins
hormonal changes if LH
increases and drops at the beginning of estrus
-stimulating ovulation
hormonal change if E2 (estradiol)
-present towards the end of anestrus
-continues to rise till end of proestrus then drops
-increases a little at the end of metestrus I
-drops soon after metestrus II
hormonal changes of progesterone
-low amounts present in proestrus
-steadily increases through out estrus
-increases till end of metestrus I then drops
-goes down until metestrus II
different cytology based off of the stage a dog is in
-rounded and hundreds of cells, with nucleus indicating anestrus
-nucleated and enucleated cells indicate proestrus
-cortified cells (square and flat) indicate estrus
how long are dogs pregnant for
63 days
determining the timing for mating
-male and female should be physically mature
-swelling of vulva
-bleeding
-hormone testing available
-vaginal smears to show cell shape
what in in the blood tells if the female is ready to be mated
progesterone
things seen in different stages of heat cycle: prolactin
-in pregnant dogs is present and starts to increase at the beginning of metestrus II
-drops right at the end
natural copulation
-behaviour clues: frolicking, tail tucking, and tail flagging
-present hindquarters, tail to side
-tradition is that female goes to male
-they are territorial so male can get stresses
stages of canine mating
-first stage coitus (1-2mins)
-the turn (2-5 seconds) first 2/3 of semen deposited at this point
-second stage coitus (5-45 mins) 1/3 of very rich semen deposited
-this is the tie, bulbus glandis engorges, constrictor vestibuli muscles of vagina contract
-successful tie should last 15-20 minuites
artificial insemination
-chilled, not frozen semen
-AKC registration of pups required vet to collect and inseminate
-vaginal insemination possible
-success rate is variable
-above cervix increases success
AI success rates
-for percent whelping and litter size
-highest success to lowest
-fresh, chilled, frozen-thawed
-Intra-uterine, vaginal
selecting a mate
-inbreeding co efficient < 10%
-complement strengths and improve weaknesses
-genetics- disease, behaviour, appearance, temperament
how often should dogs be bred
-skip a heat between whelping
-larger litter
-healthier pups
-improved longevity for bitch
-wild canids have one litter per year
male reproduction problems
-frozen testicles (> or eq to 60 days loss of viable sperm)
-steroids (prednisone for allergies)
-brucellosis bacterial infection that renders a male sterile)
-cryptorchidism
-normal decent of testicles 7-10 days
female reproductive problems
-tumors, cysts
-chromosomal abnormalities
-false pregnancy (prolacting, same as pregnant)
-60 days after estrus
-may lactate, gain weight
-may display nesting behaviour
breeding and age
-males sperm count declines by 9 years
-females not bred by 5 may have greater risk of whelping problems
-most bitches retire around 6
induced estrus
-one female in heat, causes heat cycles to begin in other females
-litters would be closer together then ideal in a kennel with multiple litter/year
