Intro to repro Flashcards
What is the primary control of reproductive hormone secretion in females?
Negative feedback from sex steroids (e.g., progesterone and oestrogen) on GnRH and gonadotropins (LH, FSH).
What is the purpose of GnRH and steroid use in reproductive hormone regulation?
To block or stop GnRH stimulation and use reproductive sex steroids for negative feedback.
What are Depot progestogens (e.g., Proligestone)?
Temporary prevention of estrus, administered via injection at specific intervals (e.g., every 5 months).
What is the function of GnRH Superagonists (e.g., Deslorelin)?
Induces temporary infertility in female and male dogs (and male cats), with repeat implants every 6-12 months.
How do depot androgens work in reproductive control?
Off-license use of weakly androgenic progestogens (e.g., Norethisterone) for temporary infertility, often used in racing greyhounds.
What is the typical oestrus cycle of a dog?
Ovulation occurs 21 days after the first signs of estrus; progesterone is elevated for about 15 days.
What is the reproductive cycle of a bitch?
Monoestrus cycle with an interval of 7 months. Ovulation is spontaneous, and there is a long luteal phase.
How does prolactin influence pregnancy in bitches?
Prolactin supports the corpus luteum and is important for maintaining pregnancy.
What is unique about a queen’s reproductive cycle?
Seasonal and polyoestrus. Induced ovulation occurs, with the LH surge being triggered by mating.
What triggers ovulation in queens?
Mating triggers a large LH surge that induces ovulation. LH concentrations must exceed a threshold.
How does a queen’s cycle differ if she ovulates or doesn’t?
Ovulation leads to progesterone increase and either pregnancy or pseudo-pregnancy. No ovulation leads to the disappearance of oestrus signs.
What is a challenge when timing breeding in dogs?
Ovulation day is variable, and many breeders mistakenly choose the wrong breeding day.
How can progesterone be used to manage breeding timing in dogs?
Repeated progesterone testing starting on Day 7 helps identify the optimal breeding window.
What is an effective management plan for breeding timing in cats?
Ensure mating occurs on Day 3 of estrus, with multiple breedings allowed. Ovulation may be induced with hCG or GnRH.
What factors should be considered when investigating a dog with odorous vulval discharge?
Clinical history, venereal pathogen screening, general clinical and specific reproductive exams.
