Reproduction Flashcards
what are 3 methods to induce estrus in the dog?
- dopamine agonist
- GnRH / GnRH agonist
- Gonadotropins
Cabergoline
MOA?
dopamine agonist - work on hypothalamus
inhibits prolactin which induces onset of estrus
Deslorelin
MOA?
GnRH agonist - induces estrus but followed by prolonged period of anestrus = down regulation of GnRH R transciption
Cons of using GnRH for estrus induction
injectable, pulsatile nature
narrow dose range
Cons of using GnRH agonist for estrus induction
constant stimulation will eventually cause down regulation of pituitary (low LH/FSH)
what method to induce estrus has the highest chance of success
dopamine agonist (cabergoline)
Why are gonadotropins (LH/FSH) a poor choice for estrus induction
poor ovulation rate
limited availability
what are the 3 methods of estrus suppression in the dog?
- surgery
- steroids
- GnRH agonists
which method of estrus suppression is best, 100% success?
surgery (OHE/OE)
what are the two steroid options for estrus suppression?
progestogens (MPA, MA)
androgens (mibolerone, testosterone)
Progestogens
(Medroxyprogesterone “MPA” & Megestrol Acetate “MA”) MOA
unknown - LH/FSH levels increase during the first few months of therapy
Progestogens
(Medroxyprogesterone “MPA” & Megestrol Acetate “MA”) side effects
CEH / pyometra
endometritis
mammary development
mammary neoplasia
alopecia, coat color change
increased appetite
weight gain
lethargy
Androgens (mibolerone, testosterone) MOA
negative feedback causing decreased secretion of gonadotropins at the level of hypothalamus and likely pituitary
which method of estrus suppression is the only product approved in the US
progestogens
Cons of using Androgens for estrus suppression
limited supply/no product approved for use in the US
potential side effects (clitoral hypertrophy, vaginitis, discharge, behavior, epiphora, liver enzymes)
how is GnRH agonists (Deslorelin) an estrus inducer and also estrus suppressor? what are its cons?
initial estrus followed by prolonged anestrus (2yrs)
not approved in US for dogs
side effects but are reversible
less predictable
how is mismating (pregnancy termination) done in the canines
no meds approved for canine abortion in US - its off-label
1. surgery - OHE
2. corticosteroids (dexamethasone)
3. estrogens
4. prostaglandins
5. dopamine agonist
6. progesterone R antagonist
most abortion protocols suggest what prior to treatment?
confirming pregnancy prior to treatment
are corticosteroids and estrogens generally recommended as abortifacients in dogs?
NO
estrogen (estradiol cypionate) MOA in terms of abortion
inhibits oocyte migration & implantation of embryo
SEVERE SIDE EFFECTS
prostaglandins MOA in terms of abortion and why must these patients be hospitalized?
PGF2alpha - luteolysis
dinoprost (lutalyse) - naturally occuring PG
cloprostenol (estrumate) - synthetic PG
significant, severe side effects - hypotension/circulatory collapse
which prostaglandin is the one that can be used in dogs? when?
PGF2alpha
28-30 days post LH due to canine CL resistance early in diestrus
why can dopamine agonists (cabergoline) be used for terminating pregnancy?
inhibiting prolactin cuts off CL support and pregnancy maintenance
progesterone receptor antagonist (Aglepristone) MOA
competitively binds/antagonizes progesterone receptors at target organs
ends diestrus, also treatment for pyometra
special import needed for US use
what is considered persistent estrus?
~30 days
four causes of persistent estrus?
- granulosa cell tumor
- follicular cyst
- anovulatory follicle
- exogenous estrogen exposure
what are 3 problems arising from a bitch cycling too frequently
normal q 7 months
1. infertility
2. overstim of ovaries
4. overstim of endometrium
common signalments of a dog with mastitis?
nursing bitch (small or large litters)
firm, reddened, painful mammary glands
most common mastitis etiology in the dog?
galactostasis (milk /gland congestion) resulting in ascending infection (E.coli, Staph, Strep)
most common mastitis clinical signs in the dog?
hot painful glands
fever at peak, 2-3 weeks
lethargy, anorexia
poor maternal behavior
pups not gaining weight
canine mastitis treatment
cytology + culture
supportive care
pain meds/abx (start with beta lactam broad spectrum)
keep glands expressed (hand strip, nursing)
what are the 3 most common post partum disorders in the dog that cause a fever?
mastitis
postpartum metritis
eclampsia
what are the two risk factors that can result in a dog having agalactia (no milk production)
premature
progesterone during gestation
what are the most common cells found on a cytology of postpartum metritis?
parabasal cells
degenerate neutrophils
postpartum metritis clinical signs?
purulent vulvar discharge
fever within 2-3 days
postpartum metritis risk factors?
abortion, fetal infection, dystocia, retained fetal membranes leading to ascending infection
what are the risk factors of eclampsia in the bitch?
- small breeds with large lactation demands
- large litters
- calcium supplementation during pregnancy (down regulates normal Ca regulation)
most common signalment of eclampsia in dogs?
small breeds during peak lactation (2-3 weeks) w/ large litters having panting, restlessness, tremors, muscle spams, behavior changes
eclampsia etiopathogenesis in the dog
inappropriate mobilization of calcium stores = hypocalcemia = lower threshold potential of Na channels = excitatory effect and tetany
Subinvoluted Placental Sites (SIPS) presumptive etiopathogenesis
endometrial eosinophilic inflam caused by trophoblastic cell migration = persistent bleeding due to lack of thrombosis and uterine involution
Subinvoluted Placental Sites (SIPS) clinical signs
persistent serosanguinous vulvar discharge (>3 weeks postpartum)
Subinvoluted Placental Sites (SIPS) diagnosis
must rule out metritis, vaginitis, clotting disorders
blood work WNL
US of uterus normal
Subinvoluted Placental Sites (SIPS) treatment
supportive
OHE if necessary
