Lecture 22,23 - Functional Infertility (endocrine disorders of reproduction) Flashcards
How do inactive ovaries lead to functional inferitlity?
No egg to fertilize - anovulation
How do silently active ovaries lead to functional infertility?
No breeding
How can you determine if ovaries are active?
Palpation and U/S
If the female has never shown signs of estrus, and her ovaries are not currently active, what are 4 differentials?
Seasonal anestrus
Chromosomal abnormality
Anabolic steroid therapy
Prebuberal
If we know a calf was born co-twin to the opposite sex, examine the female within the first 30 days after birth with a test tube. What do the results indicate?
If a 10 mL test tube will not pass to full length of the vagina, the cow is a freemartin
How to detect prepubertal animals
Weigh heifers/ewe lambs - if female weight is not at least 60% of her anticipated adult body weight, most likely pre-pubertal.
Reproductive tract scores in beef heifers
Concept of reproductive tract scores in beef heifers
Formal process in which we try to estimate whether the heifer has gone through puberty or is close to going through pubery (based on 1-5 scorying system).
The lower the score, the further she is from being a cycling female.
What is the main thing a cow will have that will determine if she has gone through puberty?
A CL
Alpacas can reach puberty at any time between __ and __ months.
18-36
If a female has never shown signs of estrus, and her ovaries are currently active, then she must be in ______ ______.
Silent estrus
Reasons for silent heat in a cow?
Post partum, hot weather, disease, Bos indicus breed, housing
Reasons for silent heat in the ewe
First cycle of the season
Reason for silent heat in the mare
Foal by side
Silent heat can be easily mistaken with ________
Poor teasing/heat detect
If a female has not shown signs of estrus during hte last few months, but has shown estrus previously, what question do you need to ask next?
Is she pregnant
If a female has not shown signs of estrus during hte last few months, but has shown estrus previously, is not pregnant, and does not have active ovaries, what are your differentials?
Seasonal anestrus
Lactational anestrus
Pituitary tumor
Severe malnutrition
Persistent endometrial cups (mare)
Three things that dictate true anestrus that can be found on transrectal palpation and U/S:
No ovulatory follicles
no CL
No cycles
Reasons for true anestrus:
- Poor nutrition (dairy cow)
- Lactation (beef cow, sow)
- Normal in bitch up to 12 months post partum
- Season
- Pituitary tumor
- REproductive sensecense
How do pituitary tumors lead to anestrus?
supress ability of the pituitary to release LH and FSH
If a female has not shown signs of estrus during hte last few months, but has previously shown signs of estrous, is not pregnant, and only has one ovary active (one larger, and one inactive), list the differentials:
Granuolsa cell tumo
Cystic ovarian disease
T/F: Granuolsa cell tumors are an old animal cancer.
False!!
Granuolsa theca cell tumors occur in virutally all species. However, what two species in particular do they play an improtant role in?
Horse and dog
Granuolsa-theca cell tumors give rise to increased levels of _____ in the dog.
estrogen
Dogs with GTC tumor wil persistently be in what stage of their estrous cycle?
Proestrus
Why do dogs present with anemia with a GTC tumor?
Persistently in proestrus due to hyperestrogenism (estrogen secreted by the tumor) - losing so much blood through leakage from the endometrium
By the time the mare is presented to the vet with GTC tumor, why do they behave “male” like?
Horses initially go through a persistent estrus phase when the GTC tumor secretes a lot of estrogen, but this phase is so short that it often goes unrecognized by the client. By the time the client brings them in, the granuolsa cells become metaplsastic and change their function, losing their ability to convert androgens into estrogens. So now the precursor to estrogen (testosterone) piles up.
Why do GTC tumors inhibit the contra-lateral ovary?
Becuase along with estrogen, they also produce inhibin.
Do granuolsa cell tumors ever lose their ability to produce inhibin? What are the consequences?
No, so FSH concentrations are rock bottom low - resulting in complete inactivity of the contralateral ovary.
Upon rectal palpation of the mare, in order to diagnose she has a GCT - what two things must you confirm?
- Large affeted ovary with NO OVULATION FOSSA
- Inactive contra-lateral ovary
What hormones can you test in the mare for GCT?
- Inhibin - high with GCT
- Testosterone - usually high with GCT
- Progesterone - absence with GCT (not cycling)
- AMH - high (GCTs secrete AMh as well)
Treatment for GCT?
Removal of the ovary
Cystic ovarian disease is a disease of which species?
Cattle
T/F: the horse may suffer from cystic ovariaion disease.
FALSE - HORSES NEVER GET CYSTIC OVARIAN DISEASE
A cows CL is highly vascularized. Upon U/S, it shoudl appear as ____ (hypoechoic or anechoic or hyperechoic).
Hypoechoic
What is a cystic CL, and what should a “cystic” CL be referred to? Why?
A cystic CL is a developmental stage of the young CL, and it should be referred to as a hollow or cavitous CL b/c it is stil a CL but with a fluid filled cavity inside of it.
On U/S, a cystic CL appears _____ (hypoechoic, anechoic, or hyperechoic).
anechoic - fluid filled center
is a “cystic” CL in the bovine equivalent to cystic ovarian disease?
NO! Cystic CL are normal - developmental stage of the CL!!!!!!!