Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
17 Cards in this Set
- Front
- Back
What is the traditional definition of cystic ovarian syndrome?
|
Follicular (fluid-filled) structure >2.5cm, persisting >10d in the absence of a CL
|
|
What is the functional definition of COS?
|
Anovulatory follicle >/= 17mm, absence of CL inducing altered cyclicity, with ovarian follicular waves continuing and dominant follicles persisting ~13 days
Lack of uterine tone! NO ovulation, NO LH surge |
|
What are possible outcomes of COS?
|
Cyst persists: 10-20%
Cyst turnover: 51-56% Spontaneous recovery: 20-60% |
|
What are predisposing factors of COS?
|
2nd and greater lactation
Early lactation High milk yield Summer calving Fat cows/ketosis Stress (Cortisol decreases GnRH, decreases LH) Health problems (uterine infection, lameness) |
|
What level of progesterone indicates a cystic follicle?
|
< or = to 1ng/mL
|
|
What is a luteinized follicle?
|
Non-pathologic!
Follicle growth- ovulation- release ovum- lutealized- has fluid in the center during transition between CH and CL |
|
What does it mean if the follicle has an ovulation papilla?
|
HAS OVULATED! NOT a luteal cyst, may be cystic CL
|
|
How do you diagnose COS?
|
On rectal palpation: follicle that is ovulation size or bigger (>17mm)
Lack of uterine Tone, Lack of CL Nymphomania persisting: sterility hump, increased relaxin U/s: Fluid filled anechoic structure within ovary homogenous texture to the uterus evaluate thickness of follicle wall/degree of luteinization V. useful for distinguishing cyst from a soft CL with no palpable papilla CL=OVULATION! |
|
Pathogenesis of COS?
|
Failure of estradiol to stimulate release of GnRH surge from the hypothalamus-- NO LH preovulatory surge, therefore the ovulation sized follicle is in a low progesterone environment- growth continues
|
|
What happens when you can't rest the hypothalamus with COS?
|
Cysts persist due to no progesterone exposure
Decreased expression of Estrogen receptor alpha |
|
What is Estrogen receptor alpha responsible for/ related to?
|
1. Initiation of GnRH signal
2. Progesterone up-regulates ER alpha 3. ERalpha becomes downregulated by Estrogen exposure |
|
What causes Decreased progesterone in COS?
|
1. Short luteal phase: CL develops but doesn't persist
2. Increased progesterone metabolism: High production dairy cattle eat a lot Increases hepatic blood flow Increases efficiency at conjugating/eliminating steroid Decreases progesterone and estrogen Decreases hypothalamus priming and increases FSH, leading to more follicles (mult ovulations/twins) |
|
What is the goal of COS treatment?
|
Conception
Increasing circulating progesterone (exposure to progesterone for 7 days restores responsiveness to estradiol) Induce ovulation of a follicle and CL formation |
|
What is a successful COS treatment defined as?
|
Regression followed by ovulation and formation of a normal CL within 15 days
|
|
What is the best treatment for COS?
|
OVSYNCH!
1. GnRH (new follicles develop, luteinization) 2. 7 days later PGF2a (luteolysis) 3. 48 hours later GnRH (ovulation) 4. 16 hours later, timed AI |
|
How do you use a CIDR to treat COS?
|
Add progesterone via a CIDR for 7d, and PGF at removal then AI,
Or Ovsynch +CIDR increases pregnancy rates |
|
How do you prevent COS?
|
Decrease incidence of nutritional and metabolic disorders
Genetic selection Decrease stress- good transition cow management |